The invention provides a stable platform servo control system, and aims to solve the technical problems that a traditional motor servo control system cannot meet the control precision requirement of the system, mechanical resonance is difficult to restrain, and the size and the weight are large. The stable platform servo control systemincludes a DC / DC, an azimuth motor arranged on an azimuth shaft, an azimuth fiber-optic gyroscope, an azimuth encoder arranged on an output shaft of the azimuth motor, an azimuth shaft control assembly, a pitching motor arranged on a pitching shaft, a pitching fiber-optic gyroscope, a pitching encoder arranged on an output shaft of the pitching motor, and a pitching shaft control assembly. The control assembly comprises an FPGA, a DSP, a three-phase bridge, a PWM drive circuit, a current acquisition circuit, an AD conversion circuit and a communication circuit. The DSP comprises a position loop controller, a speed loop controller, a current loop controller, a digital wave trap and a PWM generator, and is used for realizing an SVPWM control algorithm or an SPWM control algorithm and a current, speed and position three-closed-loop control algorithm of an azimuth axis.