The invention discloses a hydraulic semi-active suspension for a special vehicle and a control system thereof. The hydraulic semi-active suspension is composed of a hydraulic motor, a generator, a storage battery, a DC module, four sets of energy feedback adjusting valve units and four sets of shock absorber hydraulic cylinders, and the automatic adjusting system is composed of a driving motor, ahydraulic pump, a hydraulic source oil tank, an oil filter, a low-pressure energy accumulator, a high-pressure energy accumulator, four sets of automatic adjusting valve units and four sets of shock absorber hydraulic cylinders. Eachh energy feedback adjusting valve unit consists of a switch valve and a one-way valve, and each automatic adjusting valve unit consists of a three-position four-way electromagnetic valve and an oil tank; the control method comprises an energy feedback control method and an active adjustment control method. The height of each suspension shock absorber can be adjusted according to different working conditions when emergency braking, rapid acceleration and steering are about to roll over, so that the vehicle smoothness, the operation stability and the driver safety are improved, and energy recovery is carried out when the vehicle runs linearly and stably.