The co-seismic response of water level in the Hongtong well to remote strong earthquakes were systematically analyzed since the digital transformation in 2013,and the results represented that the water level in the Hongtong well had a good response capability of recording earthquakes(M_S ≥ 7.5),and co-seismic response of the Hongtong well showed a certain direction;to different earthquakes the co-seismic response forms of water were mainly water waves,part of the water waves was given accompanied by step changes and the initial direction of co-seismic step change was mainly rising. Statistical analysis showed that the amplitude of water level had a poor correlation with the epicentral distance and magnitude,and the epicentral response time had a quantitative relationship with the epicentral distance. Further verification indicated that the most of co-seismic responses were caused by S-wave,some of which being surface waves,or P-wave and the change of water level caused by S-wave is smaller than that of P-wave,among which the surface wave is the largest. In this paper,the mechanism of water level oscillation of the predecessors' research was analyzed,and the preliminary discussion on its related mechanism was given combining the Hongtong well specific circumstances change.