Abstract: The water temperature of earth tide at Yongqing Seismic Station have repeatedly risen and dropped abruptly since December 30, 2017. However, the water level of the same well has not changed significantly. Through comparison test, cold water injection test, power failure test and other series of verification, it is believed that the abnormal change of water temperature in Yongqing well is not caused by interference. Through the analysis of the corresponding relationship between the abnormal change of water temperature and the earthquake, it is believed that the abnormal water temperature in Yongqing well may be related to the earthquake.