A multi-redundancy electromechanical servo system for regulating a liquid rocket engine, comprising a triple-redundancy servo controller (1), a double-redundancy servo driver (2), double-winding electromechanical actuators (4, 5), a triple-redundancy position sensor (6), a thrust regulator (8) and a mixed ratio regulator (9). Engine thrust, a mixed ratio regulation instruction and a feedback signal of the triple-redundancy position sensor are inputted to the triple-redundancy servo controller, and the triple-redundancy servo controller outputs thrust and mixed ratio regulation PWM wave control signals to the double-redundancy servo driver. The double-redundancy servo driver outputs a three-phase variable-frequency variable-amplitude sine wave current to drive the double-winding electromechanical actuators to drive the thrust regulator and the mixed ratio regulator to move, thus achieving engine thrust and mixed ratio regulation. The present servo system has a simple system and excellent control characteristics, has the ability to “control a two-degree fault operation and drive a one-degree fault operation”, and significantly improves the reliability and usage maintainability of the thrust and mixed ratio regulation of the liquid rocket engine. Also disclosed is a method for implementing the foregoing multi-redundancy electromechanical servo system.