Abstract: To further improve the fault location accuracy of AC microgrids,a Beidou fault location method of AC microgrids based on ARM model is proposed in this paper. Based on the architecture diagram of AR7615 reduced instruction set microprocessor,a 32-bit reduced instruction set microprocessor is composed of single instruction stream multiprocessor and data stream coprocessor.According to the Beidou satellite space coordinates and receiver azimuth coordinates,the pseudo range single point positioning is completed by using quaternion nonlinear equations. Through steps of establishing irregular triangular network,capturing equivalent points and fitting contour lines,the visual processing of Beidou location of AC microgrid fault is realized. The analysis results show that the proposed method has good effectiveness with the support of communication network signals,and the positioning quality of single target fault point is high and the geographic coordinate error is small.