The integration trend of the power system is the current consensus in the industry, but the specific issues such as which high-voltage components to integrate, how to integrate, and the depth of integration have yet to be solved. In the current market of battery electric vehicle rear drive power system, most of the high-voltage components only integrated reducer, other high-pressure components arranged in the rear compartment, so the whole rear drive system is relatively complex, the relevant high-voltage lines and cooling water is more complex, and the cost is higher. [0006] 2, the rear passenger and luggage compartment space is smaller [0007] Since the rear drive power system generally needs to be equipped with motors, reducers, motor controllers, high-voltage lines, cooling water pipes, and some charging ports behind the charger, high-voltage line distribution boxes, etc., these will inevitably affect the rear passenger space and luggage compartment space. [0008] 3, cooling water and high pressure circuit staggered [0009] In the narrow space of the rear cabin, it is not easy to arrange so many parts of the power system. Most manufacturers can no longer consider the reasonable partition of the rear drive cooling water and the high pressure circuit, which is bound to leave hidden dangers for the collision safety of the rear drive power system. [0010] 4, electromagnetic interference problems [0011] The problem of electromagnetic interference in battery electric vehicle has been existed for a long time. Avoid high-voltage line on low-voltage signal parts battery interference is equally important, because the rear drive power system layout space is extremely tight, the domestic host plant can only strengthen the electromagnetic protection of parts to overcome, the effect is limited.