The invention discloses a hybrid power drive system for an aircraft. An engine is directly connected to a transmission shaft in a mechanical transmission manner, two sets of main rotor wings connectedto a control system are connected to and installed at the two ends of the transmission shaft in a mechanical transmission manner, at least one electric generator is installed on the engine, and the electric generator is connected to the control system. At least two sets of auxiliary rotor wings are installed at the position, located between the two sets of main rotor wings, of an aircraft body frame, the auxiliary rotor wings are driven by a motor and are powered by the electric generator, and the motor is connected to the control system. By means of the hybrid power drive system, the transmission mode and the transmission structure are greatly simplified, simple transmission components and structures reduce the overall weight of transmission members, and energy lost during transmission is also reduced. In cooperation with the electric generator with the low energy consumption demand, the generated electric energy is supplied to the auxiliary rotor wings and the control system to be used, the mechanical transmission provides main lifting force, so that the energy loss of power conversion is saved, best control over the energy loss is achieved, and the flight capability and the flight quality of the aircraft are effectively and significantly improved.