Aimed at the weakness of traditional injection molding machine, like large energy consumption and low efficiency and etc., an intelligent digital servo control system which based on digital signal processor (DSP) and field programmable gate array(FPGA) was put forward. By using closed-loop control strategy of combining the traditional PID and fuzzy control, the energy-saving, high-precision and intellectualization of injection molding machine were realized. It was simulated in the MATLAB/Simulink environment, and proceeded on-site debug and functional verification. The experimental results show that after having modified the intelligent digital control system, as compared with the machine before modification, the injection molding machines energy consumption can be reduced by 50%, and which of the large power machine can even reach up to 70%, and the refined machine also has a good robustness.