Aiming to solve the problem that traditional rear-wheel-drive heavy-duty commercial vehicles and engineering vehicles can not meet the requirement for power performance on low-adhesion coefficient pavements, heavy-gradient pavements and separated pavements, the invention provides a hub motor hydraulic hybrid power system. A hydraulic pump takes power from an engine through a power taking device; and a control unit outputs different control commands to enable a control valve bank to be switched to different working positions to realize multiple working modes including a freewheel mode, a hydraulic pump drive assistance mode, an energy accumulator drive assistance mode, a braking energy recovery mode and a parking charging mode. The hub motor hydraulic hybrid power system provided by the invention increases the power of an entire vehicle, improves the traction efficiency of the entire vehicle, and reduces the oil consumption of the engine by recovering part of vehicle braking energy so as to realize energy-saving and environment-friendly effects; and the hub motor hydraulic hybrid power system facilitates engineering realization and has better application prospects.