Abstract: For the existing problem of GNSS receiver in the indoor environment facing for strong signal attenuation, the NLOS propagation and cross correlation effects, this text proposes a coarse time navigation and RAIM algorithm to solve the problem of AGNSS indoor positioning and use BDS data to verify the reliability of the method. The experiment showed that the coarse time navigation algorithm is able to provide successive and reliable positioning results. It can also be used in weak signal environments. RAIM algorithm based on a combination FDE can increase the availability of the positioning result and solve the problems of NLOS propagation and cross correlation effects of indoor satellite signals. The AGNSS technology based on coarse time navigation and RAIM algorithm can be applied to indoor positioning, and its simulation result of horizontal RMS is less than 10 m.