diff --git a/README.md b/README.md
index ed51700..da63917 100644
--- a/README.md
+++ b/README.md
@@ -94,7 +94,8 @@ SOPS 文件、运行时 env、SSH key 或 mihomo 配置。
 - `Enter`：仅在目标在线时进入其 controller 详情。
 - `r`：刷新连通性状态。
 - `t`：对当前 Selector 组的候选节点做 mihomo delay 探测；默认使用
-  `https://www.gstatic.com/generate_204`，最多并发 4 个。
+  `https://www.gstatic.com/generate_204`，最多并发 4 个。每个 candidate 完成后会立即
+  更新 delay 和当前推荐，慢节点或超时节点不会阻塞先完成的结果显示。
 - `s`：对当前选择的候选节点发起运行态切换。TUI 会显示机器、组、旧节点和新节点，
   必须按 `y` 二次确认；成功后立即读取 controller 验证当前节点。
 
diff --git a/proxy_monitor_tui.py b/proxy_monitor_tui.py
index 22363f2..b6c5320 100644
--- a/proxy_monitor_tui.py
+++ b/proxy_monitor_tui.py
@@ -8,7 +8,7 @@ import json
 import os
 from pathlib import Path
 import sys
-from typing import Any
+from typing import Any, Iterator
 import urllib.error
 import urllib.parse
 import urllib.request
@@ -287,7 +287,7 @@ def recommend_fastest(delay_results: dict[str, tuple[int | None, str]]) -> str |
     return min(successful)[1] if successful else None
 
 
-def measure_candidates(
+def iter_measure_candidates(
     client: ProxyMonitorClient,
     target_name: str,
     candidates: list[str],
@@ -295,9 +295,9 @@ def measure_candidates(
     test_url: str,
     timeout_ms: int,
     concurrency: int,
-) -> dict[str, tuple[int | None, str]]:
+) -> Iterator[tuple[str, tuple[int | None, str]]]:
+    """Yield each candidate result as soon as its controller request finishes."""
     unique_candidates = list(dict.fromkeys(candidate for candidate in candidates if candidate))
-    results: dict[str, tuple[int | None, str]] = {}
 
     def measure(candidate: str) -> tuple[int | None, str]:
         try:
@@ -316,9 +316,32 @@ def measure_candidates(
         for future in as_completed(futures):
             candidate = futures[future]
             try:
-                results[candidate] = future.result()
+                yield candidate, future.result()
             except Exception as exc:  # noqa: BLE001
-                results[candidate] = (None, str(exc))
+                yield candidate, (None, str(exc))
+
+
+def measure_candidates(
+    client: ProxyMonitorClient,
+    target_name: str,
+    candidates: list[str],
+    *,
+    test_url: str,
+    timeout_ms: int,
+    concurrency: int,
+) -> dict[str, tuple[int | None, str]]:
+    """Collect all candidate results for non-interactive callers."""
+    unique_candidates = list(dict.fromkeys(candidate for candidate in candidates if candidate))
+    results = dict(
+        iter_measure_candidates(
+            client,
+            target_name,
+            unique_candidates,
+            test_url=test_url,
+            timeout_ms=timeout_ms,
+            concurrency=concurrency,
+        )
+    )
 
     return {candidate: results.get(candidate, (None, "not run")) for candidate in unique_candidates}
 
@@ -431,6 +454,7 @@ def run_textual(
             self.target = target
             self.groups_by_name: dict[str, dict[str, Any]] = {}
             self.delay_results: dict[str, dict[str, tuple[int | None, str]]] = {}
+            self.delay_test_runs: dict[str, int] = {}
             self.selected_group = ""
             self.selected_node = ""
             self.pending_switch: tuple[str, str] | None = None
@@ -537,27 +561,69 @@ def run_textual(
             if not group:
                 self._set_operation("choose a Selector group first")
                 return
-            self._set_operation(f"testing {len(as_list(group.get('candidates')))} candidates...")
-            self.test_selected_group(str(group["name"]), list(as_list(group.get("candidates"))))
+            group_name = str(group["name"])
+            candidates = list(dict.fromkeys(str(candidate) for candidate in as_list(group.get("candidates")) if candidate))
+            run_id = self.delay_test_runs.get(group_name, 0) + 1
+            self.delay_test_runs[group_name] = run_id
+            self.delay_results[group_name] = {}
+            self._show_group(group_name)
+            self._set_operation(
+                f"testing {len(candidates)} candidates; each completed delay appears immediately..."
+            )
+            self.test_selected_group(group_name, candidates, run_id)
 
         @work(thread=True, exclusive=True)
-        def test_selected_group(self, group_name: str, candidates: list[str]) -> None:
-            results = measure_candidates(
+        def test_selected_group(self, group_name: str, candidates: list[str], run_id: int) -> None:
+            total = len(candidates)
+            for candidate, result in iter_measure_candidates(
                 client,
                 str(self.target["name"]),
                 candidates,
                 test_url=test_url,
                 timeout_ms=test_timeout_ms,
                 concurrency=delay_concurrency,
+            ):
+                self.app.call_from_thread(
+                    self._record_delay_result,
+                    group_name,
+                    run_id,
+                    candidate,
+                    result,
+                    total,
+                )
+            self.app.call_from_thread(self._finish_delay_test, group_name, run_id)
+
+        def _record_delay_result(
+            self,
+            group_name: str,
+            run_id: int,
+            candidate: str,
+            result: tuple[int | None, str],
+            total: int,
+        ) -> None:
+            if self.delay_test_runs.get(group_name) != run_id:
+                return
+            results = self.delay_results.setdefault(group_name, {})
+            results[candidate] = result
+            completed = len(results)
+            recommended = recommend_fastest(results)
+            if group_name == self.selected_group:
+                self._show_group(group_name)
+            delay, detail = result
+            latest = f"{delay} ms" if delay is not None else detail
+            self._set_operation(
+                f"testing {completed}/{total}; {candidate}: {latest}; "
+                f"best so far: {recommended or 'none'}"
             )
-            self.app.call_from_thread(self._finish_delay_test, group_name, results)
 
         def _finish_delay_test(
             self,
             group_name: str,
-            results: dict[str, tuple[int | None, str]],
+            run_id: int,
         ) -> None:
-            self.delay_results[group_name] = results
+            if self.delay_test_runs.get(group_name) != run_id:
+                return
+            results = self.delay_results.get(group_name, {})
             recommended = recommend_fastest(results)
             if group_name == self.selected_group:
                 self._show_group(group_name)
diff --git a/pyproject.toml b/pyproject.toml
index f2e01f2..09e822b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "proxy-port-monitor-tui"
-version = "0.1.1"
+version = "0.1.2"
 description = "Terminal UI for proxy-port-monitor and mihomo selector groups"
 readme = "README.md"
 requires-python = ">=3.11"
diff --git a/tests/test_proxy_monitor_tui.py b/tests/test_proxy_monitor_tui.py
index ece29e9..1afd5a7 100644
--- a/tests/test_proxy_monitor_tui.py
+++ b/tests/test_proxy_monitor_tui.py
@@ -163,6 +163,37 @@ class ProxyMonitorTUITests(unittest.TestCase):
         )
         self.assertEqual(recommended, "fast")
 
+    def test_delay_results_are_yielded_before_slower_candidates_finish(self) -> None:
+        class ControlledClient:
+            def __init__(self) -> None:
+                self.slow_started = threading.Event()
+                self.release_slow = threading.Event()
+
+            def measure_delay(self, _target: str, candidate: str, **_kwargs: object) -> int:
+                if candidate == "slow":
+                    self.slow_started.set()
+                    self.release_slow.wait(timeout=2)
+                    return 300
+                self.slow_started.wait(timeout=2)
+                return 42
+
+        client = ControlledClient()
+        stream = self.mod.iter_measure_candidates(
+            client,
+            "pc",
+            ["slow", "fast"],
+            test_url="https://www.gstatic.com/generate_204",
+            timeout_ms=5000,
+            concurrency=2,
+        )
+        try:
+            candidate, result = next(stream)
+            self.assertEqual(candidate, "fast")
+            self.assertEqual(result, (42, "42 ms"))
+        finally:
+            client.release_slow.set()
+        self.assertEqual(list(stream), [("slow", (300, "300 ms"))])
+
     def test_machine_rows_preserve_monitor_order_and_status(self) -> None:
         rows = self.mod.normalize_machine_rows(
             {
diff --git a/uv.lock b/uv.lock
index 20f24e0..42f6ba3 100644
--- a/uv.lock
+++ b/uv.lock
@@ -63,7 +63,7 @@ wheels = [
 
 [[package]]
 name = "proxy-port-monitor-tui"
-version = "0.1.1"
+version = "0.1.2"
 source = { editable = "." }
 dependencies = [
     { name = "textual" },