Abstract: At present, coal mine local ventilator system mainly adopts conventional PID control algorithm to carry out frequency-conversion speed-regulation，but the conventional PID control parameter adjustment mainly relies on artificial experience, adjustment time is long, real time is poor, and easy to occur over-regulating and oscillating output of the control quantity. To solve the above problems, a particle swarm optimization (PSO) optimized PID control algorithm was proposed and applied to the speed control of coal mine local ventilator. PSO algorithm is added to the speed control system of coal mine local ventilator based on the conventional PID control algorithm to realize PID control parameter optimization. The conventional PID control part directly runs in accordance with the optimal parameter setting obtained by Z-N tuning method; PSO optimized PID control part randomly generated a set of three-dimensional particles through the algorithm program of S function, and calls the function assignin to assign three-dimensional particles values to Kp，Ki，Kd parameters of speed control system simulation model, taking control system error indicator ITAE as fitness function for iterative optimization, unity of PSO optimization and PID parameter setting optimization is realized.The simulation results show that compared with the conventional PID control, after PSO algorithm optimization, the output performance of local ventilator speed control are improved significantly, especially the overshoot and the regulation time index, and the overshoot is only 20% of the conventional PID control algorithm.