An isomorphism type masterslave hydraulic manipulator was presented. Applying linear grating as the main hand position detecting device, applying stepping type electric push rod to drive the slave hand, a new type of hydraulic transmission was designed and the hydraulic device was used to transfer power. The pulses generated by master hand linear grating were processed by the hardware circuit, then they were directly as the control pulses of the stepping electric push rod. Through hydraulic transmission device, the stepping electric push rod transferred the motion to the slave hand,so the slave hand could completely repeat the movements of the main hand realtime.