Abstract: To investigate the effect of differential code bias on Quasi-Zenith Satellite System(QZSS) pseudorange single-point positioning, this paper derives a differential code bias(DCB) and timing group delay(TGD) correction model for QZSS pseudorange single-point positioning, and selects 6 Multi-GNSS Experiment(MGEX) stations for 7 day of continuous observation data to conduct experiments according to two different schemes. The results show that the monthly stability of DCB products is good without obvious fluctuations, and the monthly stability of each satellite is better than 0.2 ns, and the mutual difference value with TGD is better than 2.5 ns. The impact of TGD/DCB correction on SPP accuracy is of meter level, and the horizontal positioning accuracy can be improved from 4–9 m to 3–6 m after TGD/DCB correction, and the elevation direction can be improved from 7–9 m to 5–7 m, and the improvement rate is about 10%–46%, which shows that DCB has a large impact on the single-point positioning accuracy and cannot be ignored in the positioning solution.