To improve the shearer drum height control accuracy, the initial firefly algorithm was improved. The mathematical model of the shearer drum height adjustment control system was proposed, the improved firefly algorithm was used to optimize the PID parameters of the system, and the Simulink simulation model of the drum height adjustment control system was built; the response of the improved and initial firefly algorithm system were analyzed. The results show that when the step signal, slope signal and different types of interference signals are applied to the system, the response performance and anti-interference performance of the PID controller based on improved firefly algorithm are improved obviously; under step signal, the overshoot is reduced by 21.6%; under slope signal, the optimized overshoot is reduced by 38.4%; under pulse interference signal, the optimized overshoot is reduced by 21.9%; under step interference signal, the optimized overshoot is reduced by 33.2%;and under random interference signal, the optimized response curve ripple range is reduced by 40.1%.