Abstract: In order to study the influence of different differential code bias (DCB) products on BDS-3 pseudorange single-point positioning, the BDS-3 single-frequency and dual-frequency ionospheric-free combined pseudo-range single-point positioning satellite-side DCB correction model was derived, based on the two DCB products released by the Multi-GNSS Experiment (MGEX), the Chinese Academy of Sciences (CAS) and the German Aerospace Center (DLR), combined with the BDS-3 measured data from the International GNSS Service (The International GNSS Service, IGS) stations evenly distributed in different latitudes around the world for 7 days of B1I, B1C and B2a single frequency and B1C/B2a, B1I/B3I two commonly used nonionospheric combined pseudorange single-point positioning accuracy for comparison and analysis. The results show that in the three Lfrequencies of B1I, B1C, and B2a and the two combinations of B1C/B2a and B1I/B3I, the positioning accuracy of CAS products after correction is better than that of DLR products as a whole.