Control method for power system of automatic transmission automobile

The invention provides a control method for a power system of an automatic transmission automobile. The engine revolution speed in the upshifting process is controlled by controlling output torque of an engine and pressure of a lock-up clutch of a hydraulic torque converter in the gear shifting process. By controlling the output torque of the engine and the pressure of the lock-up clutch of the hydraulic torque converter in the gear shifting process, the control method can enable the engine revolution speed to be kept in a constant range, and therefore a driver does not perceive the gear shifting process through the change of the engine revolution speed; and the influence of inertia torque on gear shifting can be effectively lowered, and meanwhile the negative effects that combustion is not sufficient, and the use efficiency of fuel oil is reduced are not caused.