The invention belongs to the technical field of hybrid power supply, and discloses a start and power generation integrated unmanned aerial vehicle miniature hybrid power system and a start method. Thesystem comprises a two-stroke piston engine, a start and power generation integrated motor, a position sensor, a motor controller, and a power source, a rotor shaft of the start and power generationintegrated motor is coupled to a crankshaft of the two-stroke piston engine, the motor controller includes a driving circuit, a rectifying circuit, a charge-discharge circuit, a first diode, a seconddiode and a two-way relay, the driving circuit comprises a driving chip, one end of the rectifying circuit is connected with the power source, and the other end of the rectifying circuit is grounded,the output end of the rectifying circuit is connected with the start and power generation integrated motor, the charge-discharge circuit comprises a first super capacitor and a second super capacitor,the first super capacitor is connected with the first diode in series to form a first series circuit, the second super capacitor and the second diode are connected in series to form a second series circuit, and the first series circuit and the second series circuit are connected with the rectifying circuit in parallel. The system has the advantage of reducing start resistance and resistance moment fluctuation.