Based on the data of small earthquakes in the Yangjiang area from 2010 to 2016,the paper revised the dense earthquakes surrounding the Pinggang fault and the Chengcun fault during the Yangjiang M_S6.4 earthquake by double-difference method and obtained 1411 relocated focus source parameters. According to the principle that the cluster earthquake occurs near the fault,the paper obtained the parameters of the two faults by using the simulated annealing algorithm and the Gauss-Newton algorithm. The Pinggang Fault with the strike of 258°,the dip angle of 85°,the fault length of 15km and dipping to northwest,which is very consistent with the focal mechanism of the M_S6.4 earthquake,crosses the southwest end of the sea and reaches the other side. The Chengcun Fault with the strike of 331°,the dip angle of 88°,the length of 28km,dipping to northeast,is longer than the previous data and deflects to the northeast with about 20°. The two steep faults are almost perpendicular at the offshore,and are of strike-slip motion.