When satellite navigation receiver is used in urban area

existence of multipath signal cause distortion of code autocorrelation function

resulting in a large bias between ranging result and real distance. The baseband multipath cancellation algorithm of reciever is hard to implement due to its high computational complexity. While it is difficult for detecting ability of receiver autonomous integrity monitoring（ RAIM） algorithm is limited to detect multiple failures. Propose a new method to detect ranging fault based on the idea of statistical quality control. According to output of quality control chart

adjust the weight of ranging information in positioning calculation

thus increase precision of positioning. The character of code tracking for each satellite is monitored separately

complexity of algorithm implementation is low. The simulation results demonstrate that the method can effectively indicate ranging error by multipath signal

which provides a new idea to improve location precision in urban environment.