As a result of observation pseudo-range’s oddity or jumping that effecting accuracy in the positioning of GPS, the correct positioning method was studied, the material formula and judgment rule were also given; The attenuated memory filtering of fixed pointing model was build for enhancement pointing accuracy, also the realize method was proposed; The simulation results indicate that, the method can give the correct position with solving observation pseudo-range’s oddity or jumping problem effectively, the attenuated memory Kalman filtering can achieve a higher positioning precision, and it’s also higher than that of general Kalman filtering and iterative least square.