Abstract:The PBO borehole strainmeter reaches 1 sps sampling. With the Mexico 8.1 earthquake on September 8, 2017 as an example, we analyze the seismic signals of 14 strainmeters and seismeters, showing that the seismic waves recorded by strainmeters meet the radiation law of transmission. The characteristics of the coseismic response of strainmeters and seismeters based on S-transform are analyzed for stations with different epicenter distances, and the coseismic responses of the strainmeters are very coherent with the seismeters’ signals. The frequency of the strainmeters is mainly below 025 Hz. After seismic time series data calculation, we find that, in the coseismic phase, the main direction of strain points to the epicenter.