Based on the seismic phase data recorded by the Shanxi Digital Seismic Network from January，2001 to October，2014，this study calculates wave velocity ratio vP / vS of the Shanxi region by using the Wadati method of single station and multi-earthquake，and discusses the variation of wave velocity ratio vP / vS before or after 3 earthquakes with MS≥4. 5 in 2010． The results show that the anomaly of wave velocity ratio vP / vS at remote stations occurs from 6 months to 1 year before those 3 earthquakes． The anomaly of wave velocity ratio vP / vS at near stations occurred from 10 days to 2 months before the 3 earthquakes． We can shrink the earthquake prediction location by the range of remote and near stations． The Dongshan Seismic Station result indicates that the residuals of earthquake origin time influence the variation details of wave velocity ratio vP / vS ． Therefore，we should firstly determine the residual threshold of original times at each station in the practical applications，to ensure the scientificity and stability of calculated results of wave velocity ratio．