In this paper, based on the earthquakes occurred in the Longmenshan region from 2011 to 2020, the cumulative Benioff strain in three sections were estimated. The results show that there is a step-up in the northern section of Longmenshan fault to the Jiuzhaigou M_S7.0 earthquake, and the cumulative Benioff strain uplift within one year after the earthquake is about 2 000×10⁸; there is a significant step-up in the middle section of Longmenshan fault to the Lushan M_S7.0 earthquake, and the cumulative Benioff strain uplift within one year after the earthquake is about 5 300×10⁸. Therefore, it is believed that the correlation between the middle section of Longmenshan fault and the Lushan earthquake is high, followed by that between the north section of Longmenshan fault and the Jiuzhaigou earthquake. As a description of the correlation between regional tectonic movement and corresponding earthquake, the uplift amount is of refe-rence significance to study the dynamic source, seismogenic structure, and seismogenic mechanism of earthquake. The research results also show that the time-varying slope of cumulative Benioff strain decreases prior to the earthquake, which may be the manifestation of the stress relaxation process before earthquake. This paper is just a preliminary study on the Benioff strain, and more earthquake cases are needed to study its mechanism and whether it can become a preparation index for large earthquakes.