Abstract：To explore the influence of BDS-3 single- and dual-frequency SPP TGD correction on positioning, we select the observation data of 10 MGEX stations for 30 days to carry out SPP experiments. The results show that the BDS-3 DCB product is stable within one month without noticeable jumps, and the monthly stability is better than 0.2 ns. The TGD parameters are more consistent with the DCB products, and most satellite differences are better than 2 ns. After TGD correction, the accuracy of single-frequency and dual-frequency SPP is greatly improved in both horizontal and vertical components. The improvement rate of single-frequency SPP is 17% to 70%, and dual-frequency SPP is 66% to 90%. The hardware delay deviation has a great influence on single point positioning and cannot be ignored in the positioning solution.