Abstract: In this paper, we picked out repeating earthquakes based on cross-correlation technology in Xunwu and its adjacent areas, and then detected the variations of crustal media by using coda wave interferometry method during repeating earthquakes. The results show that the linear trend of delay time in early S wave coda of most repeating earthquake pairs are very obvious, which reflects the wave velocity change of crustal media. The two repeating earthquake doublets in the south of Xunwu Station have the most obvious changes in wave velocity, the wave velocity variation relatively far away from stations is small. The area with obvious wave velocity change is consistent with the low b value area and the seismically active area.