There was a significant positive correlation between shale gas production and formation pressure coefficient in Sichuan Basin and its surrounding areas. For solving problem in formation pressure prediction of Wufeng Formation—Longmaxi Formation in Nanchuan area, the formation pressure was predicted by well to seismic integration. Based on well logging data, using the measured data as constraint condition, the formation pressure was calculated by Eaton method and improved Fillippone method. After results comparison, the improved Fillippone method was selected as prediction model and formula empirical value was established. Seismic interval velocity was obtained from high resolution pre-stack simultaneous inversion so as to improve accuracy. Compared with measured data, the errors met engineering requirement basically. It is predicted that the formation pressure coefficient of Wufeng Formation—Longmaxi Formation is between 0.8 and 1.6. The high pressure mostly distribute in the western and northern while the eastern and southern pressure are normal .The drilling target can be found according to the abnormal pressure area.