Based on the database from underground fluid national network,this paper analyzes the coseismic response changes of underground fluid water level and water temperature caused by the M_S6.9 earthquake in Menyuan. The results show that the number of coseismic responses of water level is much larger than that of water temperature. The start and end time of the coseismic response of the water level is prior to the water temperature. The coseismic response of water temperature is the secondary change of the coseismic response of water level. Finally,by comparing the two earthquakes in Menyuan,it is found that the seismic energy is the main reason for the difference in the coseismic response of the two earthquakes.