Electro-hydraulic actuator is a new type of mechanical, electrical and hydraulic integration of flexible transmission mechanism, which is composed of an actuator (cylinder), a control mechanism (hydraulic control valve group) and a power source (oil pump motor, etc.). According to the site installation space and the user's use of electro-hydraulic actuator can have a variety of structural forms (see electro-hydraulic actuator dimensions, can also be customized according to user requirements style). The electric motor drives the bidirectional hydraulic pump to output the pressure oil positively and negatively through the positive and negative rotation, and then sends it to the cylinder through the hydraulic control valve, which also realizes the reciprocating motion of the piston rod.