A cool water draining switch valve includes a valve body, a valve spool and a thermal module disposed in the valve body; the valve body has an inlet passage and a first outlet passage and a second outlet passage respectively connected to the inlet passage; the valve body is further disposed with a cool water draining passage connected to the inlet passage; the first outlet passage is connected to the cool water draining passage by a water draining hole, the second outlet passage is connected to the draining passage in unidirectional way by a check valve; a thermal port of the thermal module detects the water temperature of the draining passage, a retractable port of the thermal module opens or closes the water draining hole; when the valve spool is switched to a cool water draining mode, cool water in the inlet passage is drained to the draining passage.