The present disclosure discloses a shifting control method for a hybrid vehicle. The shifting control method includes: detecting operating parameters of the hybrid vehicle, where the operating parameters of the hybrid vehicle includes vehicle speed, vehicle acceleration as reflected from an accelerator-pedal signal and a current gear of the hybrid vehicle; determining a work mode of the hybrid vehicle; performing speed adjustment and shifting control to the first motor-generator according to a work mode and the operating parameters of the hybrid vehicle to implement shifting control of the hybrid vehicle, where the work mode includes an electric-vehicle mode and a hybrid-electric-vehicle mode. The method considers performing speed adjustment and shifting control under various working conditions. This improves smoothness and comfort of the vehicle and enlarges the use scope. The present disclosure further discloses a power transmission system of a hybrid vehicle and a hybrid vehicle.