The invention discloses a power distributor and a double-flow transmission gear for vehicles. The power distributor and the double-flow transmission gear are characterized in that a volumetric hydraulic pump is directly used as a power distribution element, a pump stator of the hydraulic pump is rotationally supported, an oil inlet of the hydraulic pump is additionally provided with a first rotary sealing channel, and an oil outlet of the hydraulic pump is additionally provided with a second rotary sealing channel, so that the power distributor can be formed by means of combination. Input mechanical energy can be distributed to obtain hydraulic energy and mechanical energy when a pump rotor and the pump stator of the power distributor rotate at differential velocities relative to a shell; the input mechanical energy can be outputted to obtain single mechanical energy when the pump rotor and the pump stator synchronously rotate relative to the shell. The power distributor and the double-flow transmission gear have the advantages that mechanical and hydraulic double-flow transmission systems of the vehicles can be simplified to a great extent after the power distributor is applied to the double-flow transmission gear for the vehicles, accordingly, the transmission systems of the vehicles are simple, and the transmission efficiency of the systems can be enhanced.