The single three-phase hybrid power system has the characteristic that the network structure is very complex. Based on signal injection method, a synthesized fault location method aimed at this characteristic is proposed in this paper. The method can fix fault segment with DC signal and fault position with AC signal. In this way, not only avoid the wrong judgment of fault branch because of the distribute capacitance, but also solve the abuse of longtime line patrol. At last, build a single three-phase hybrid power distribution model based on MATLAB to verify the feasibility of this method. The result shows that this method can improve the accuracy and efficiency of fault location.