Abstract: This paper studies the observation data of different borehole strain gauges in the same site at Yixian Station, analyze the reliability of the four-component borehole strain and its correlation with body strain, and then analyze the response of different borehole strain observations to special events. The result shows that: 1) The 4-component borehole strain observation at Yixian Station is not very self-consistent and requires field relative calibration; when performing relative calibration, the selection of difference value data is beneficial to improve the reliability of the data; 2) The Pearson correlation coefficient of S₁+S₃ and body strain is slightly higher than that of S₂+S₄ and body strain; 3) In terms of response to special events, the volume strain and the four-component borehole strain show tensile changes due to pumping disturbance, and the variation is higher than the volume strain. The correlation coefficient between volume strain and S₁+S₃ is higher than volume strain and S₂+S₄. In terms of co-seismic response, the co-seismic response of different borehole strains is consistent, and the correlation coefficient is related to the magnitude of the earthquake.