The invention relates to a master-slave hydraulic mechanical arm controller. A handheld terminal of the master-slave hydraulic mechanical arm controller comprises a microprocessor I which is respectively connected with a man-machine interface unit and an embedded master-hand controller, wherein the embedded master-hand controller comprises a microprocessor II which is respectively connected with the microprocessor I, an A/D (Analog to Digital) converter I and a serial to fiber module; and the A/D converter I is connected with a plurality of potentiometers (at each joint motion axis) of the main hand. The mechanical arm controller also comprises a microprocessor III which is respectively connected with an A/D converter II, a D/A (Digital to Analog) converter and an electromagnetic valve; and the microprocessor III is communicated with the serial to fiber module through a fiber to serial module; the A/D converter II is connected with a plurality of potentiometers (at each joint motion axis) on the mechanical arm; the D/A converter is connected with a hydraulic amplifier, a plurality of servo valves and a corresponding hydraulic cylinder; and the output shaft of the hydraulic cylinder is connected with the mechanical arm. The master-slave hydraulic mechanical arm controller has the advantages of high processing speed, low cost and stable and reliable performance.