Aiming at the problem of fault detection and identification when the receiver uses the weighted least squares position solution, a weighted RAIM algorithm is researched. First of all, the expression of satellite weights is introduced. It is pointed out that the satellite weights mainly depend on the satellite ephemeris error, ionosphere and troposphere delay error. Then the fault detection and fault identification model of weighted RAIM is obtained by adding weight matrix when constructing statistics. Finally, based on BDS data, the performance of traditional un-weighted RAIM algorithm and proposed weighted RAIM algorithm is verified by comparison. The test result shows that: in terms of fault detection, the performance of the weighted RAIM algorithm is related to the weight of the faulty satellite, while in fault identification, both methods are the same.