diff --git a/astrbot/core/star/filter/command.py b/astrbot/core/star/filter/command.py
index 31949b674c..da17335204 100755
--- a/astrbot/core/star/filter/command.py
+++ b/astrbot/core/star/filter/command.py
@@ -11,6 +11,10 @@
 from . import HandlerFilter
 from .custom_filter import CustomFilter
 
+# Preserve @nickname(ID) as one argument even when the nickname contains spaces.
+# IDs are platform-specific and may be strings (for example Slack/Lark IDs).
+COMMAND_ARGUMENT_PATTERN = re.compile(r"@[^@]*\([^()\s]+\)(?=\s|$)|[^\s]+")
+
 
 class GreedyStr(str):
     """标记指令完成其他参数接收后的所有剩余文本。"""
@@ -205,8 +209,8 @@ def filter(self, event: AstrMessageEvent, cfg: AstrBotConfig) -> bool:
         if not ok:
             return False
 
-        # 分割为列表
-        ls = message_str.split(" ")
+        # Split into arguments while preserving @nickname(ID) mentions as one token.
+        ls = COMMAND_ARGUMENT_PATTERN.findall(message_str)
         # 去除空字符串
         ls = [param for param in ls if param]
         params = {}
diff --git a/tests/unit/test_command_filter.py b/tests/unit/test_command_filter.py
new file mode 100644
index 0000000000..ca21d212a7
--- /dev/null
+++ b/tests/unit/test_command_filter.py
@@ -0,0 +1,59 @@
+import pytest
+
+from astrbot.core.star.filter.command import CommandFilter
+
+
+class FakeCommandEvent:
+    def __init__(self, message_str: str):
+        self.message_str = message_str
+        self.is_at_or_wake_command = True
+        self.extras = {}
+
+    def get_message_str(self) -> str:
+        return self.message_str
+
+    def set_extra(self, key: str, value) -> None:
+        self.extras[key] = value
+
+
+@pytest.mark.parametrize(
+    ("command_name", "message_str", "handler_params", "expected_params"),
+    [
+        (
+            "修改好感度",
+            "修改好感度 @Heaven Whisper(488267082) 64",
+            {"target": str, "value": int},
+            {"target": "@Heaven Whisper(488267082)", "value": 64},
+        ),
+        (
+            "修改好感度",
+            "修改好感度 @Jane Doe(U01ABC-DEF) 64",
+            {"target": str, "value": int},
+            {"target": "@Jane Doe(U01ABC-DEF)", "value": 64},
+        ),
+        (
+            "修改好感度",
+            "修改好感度 488267082 64",
+            {"target": str, "value": int},
+            {"target": "488267082", "value": 64},
+        ),
+        (
+            "修改关系",
+            "修改关系 @Alice One(U1) @Bob Two(U2)",
+            {"source": str, "target": str},
+            {"source": "@Alice One(U1)", "target": "@Bob Two(U2)"},
+        ),
+    ],
+)
+def test_command_filter_keeps_at_mentions_with_spaces_as_single_params(
+    command_name,
+    message_str,
+    handler_params,
+    expected_params,
+):
+    command_filter = CommandFilter(command_name)
+    command_filter.handler_params = handler_params
+    event = FakeCommandEvent(message_str)
+
+    assert command_filter.filter(event, cfg=None)
+    assert event.extras["parsed_params"] == expected_params