Abstract: In this study, GEODYN-Ⅱ based on PC platform was transplanted from workstation platform and, as a result, the calculation speed of the transplanted software is five to ten times higher than the speed on that platform. With the transplanted software and SELENE tracking data, the 40th degree lunar gravity coefficient model was solved, and the free air gravity anomaly field and gravity anomaly on lunar surface were built afterwards. The 40th degree free air gravity anomaly field was consistent with the results published in the magazine Science by SELENE group. In comparison with LP165Q, the 40th gravity model has higher accuracy on lunar farside. On lunar nearside, however, the 40th gravity model is not as high in accuracy as LP165P, and hence should be further improved.