Abstract: Obvious abnormal high-pressure phenomena often occur in shale gas reservoir; the pore pressure can increase greatly in a short distance. If the abnormal high-pressure values cannot be predicted timely and accurately, well kick, blowout and other drilling accidents will be caused, not only bringing great losses to drilling construction, but also seriously affecting the reservoir evaluation. However, the existing method is very difficult to predict the abnormal pore pressure value in shale gas reservoir. In combination with the experimental data of shale gas core, based on full consideration of the influences from porosity, organic matter content and effective stress on acoustic velocity, a new pore pressure prediction method for shale gas reservoir is proposed on a basis of acoustic velocity model. In this method, the relationship of P-wave and S-wave velocity in the gas-free horizons is used for gas-bearing correction at the P-wave velocity of reservoir, so as to eliminate the influences of gas on abnormal high pressure phenomenon in terms of acoustic logging information characterization. In addition, this method is able to predict the abnormal pore pressure of shale gas reservoir induced by multiple mechanisms such as unbalanced compaction and hydrocarbon generation function, thus overcoming the deficiency in the traditional method only able to predict the abnormal high pressure caused by unbalanced compaction. Well S in shale reservoir of Zhaotong area is taken as an example for reservoir pore pressure prediction, thus obtaining the technical flow of the reservoir pore pressure prediction method based on acoustic velocity model.