Abstract: Based on the near-field waveform data recorded by downhole seismometers of M≥1.0 earthquakes in the capital circle area from 2015 to 2018, the average velocity of P-wave and S-wave of 300 m in the shallow crust below the station was obtained by using the time difference between the arrival time of the direct P-wave, S-wave and corresponding surface reflection wave phase, and the horizontal distribution characteristics of the wave velocity were analyzed. The results show that the average velocity of P wave is about 1.98 km/s, the average velocity of s wave is about 0.46 km/s, and the average velocity ratio is about 4.3. 27 seismic events were located using different velocity models, the results show that the sediment model can effectively improve the north China basin earthquake location accuracy.