Abstract: The importance of SBAS in the field of precision positioning such as civil aviation is increasingly prominent, but there is currently a lack of performance comparisons between BDSBAS and WAAS in single-frequency SPP applications. Therefore, the accuracy enhancement of SBAS for single-frequency positioning is deeply analyzed. By using the IGS MGEX station data in North America and China, the single-frequency SPP positioning results of BDSBAS and WAAS GEO satellites are compared and analyzed. The improvement effect of SBAS on positioning accuracy is verified by correcting the orbit, clock error and ionospheric delay with different enhancement strategies. The results show that among all the stations, WAAS performs better than BDSBAS, with the maximum improvement of RMS reaching 60%. BDSBAS also has good adaptability in China and surrounding areas, and the maximum improvement of RMS can reach 50%. The strategy combining orbit, clock error and ionospheric delay correction, especially SF_SBAS_ORB_ION, performs best in positioning accuracy, significantly reduces errors and improves positioning stability under conditions with significant ionospheric influence. The study provides new data support and reference for the application of SBAS in single-frequency precision positioning.