The PI controller directly affects the speed regulating performance of the speed DC drive current double closed-loop system, the paper makes use of MATLAB to built two speed DC drive current double closed-loop control system simulation models respectively, one of them consists of conventional PI controller and the other one consists of fuzzy PI controller, and the line of the simulation. Simulation results show that the fuzzy PI controller is superior to the conventional PI controller in dynamic stability performance and speed tracking power, and the fuzzy PI controller has strong robustness to external disturbance.