Aiming at the low positioning accuracy of the GNSS positioning chip of the smart phone in occluded environment,this paper uses the RTK/PDR fusion method to solve the position results.Considering that the GNSS signal is susceptible to environment noise,different expansion coefficients are set to amplify the measurement noise variance matrix R in Kalman fusion filtering to realize the weight reduction of GNSS position information in occluded environment,so as to obtain better fusion results.The experimental test shows that in open environment,the positioning accuracies were identical between RTK and RTK+PDR for both two test mobile phones.While in the slightly occluded environment,compared with the RTK single positioning,the RTK+PDR fusion positioning improved the plane lifting effect of the two test mobile phones by 6.24% and 3.97%,and improved the elevation lifting effect by 20.44% and 32.56%.In the severely occluded environment,the RTK+PDR fusion positioning improved the plane lifting effect of the two test mobile phones by 47.65% and 42.90% compared with the RTK single positioning,and improved the elevation lifting effect by 39.78% and 67.98%.The experimental results show that the RTK + PDR fusion positioning method,which dynamically sets the GNSS information weight according to the average satellite carrier to noise ratio,can partially compensate for the reduction of positioning accuracy caused by environment occlusion for mobile phones using RTK.