The invention relates to a mechanical type automatic transmission gear shifting method. The mechanical type automatic transmission gear shifting method includes the following steps that the current vehicle mass and the current slope are acquired; with the maximum acceleration which a vehicle can reach as a power performance index, a best power performance gear position under different vehicle speeds, different accelerations, different accelerator opening degrees, different masses and different slopes is calculated, and serves as a vehicle power performance gear shifting strategy; with the motor efficiency being an economic index, on the basis that the slope climbing requirement of the vehicle is met, a best economy gear position under different vehicle speeds, different accelerations, different accelerator opening degrees, different masses and different slopes is calculated, and serves as a vehicle economy gear shifting strategy; and the current power performance and economy requirements of the vehicle are judged, one of the vehicle power performance gear shifting strategy and the vehicle economy gear shifting strategy is selected to determine a gear shifting point. For different masses of the vehicle and different slopes of a road, an optimal gear shifting strategy is calculated; by means of a multi-target optimization method based on road condition information and a vehicle state, the gear shifting strategies are optimized, so that the intelligent level of gear shifting can be improved, frequent gear shifting is avoided, and power performance and economy of the vehicle become best.