Abstract: In order to solve problem of damage of ranging arm of MGTY400/930-3.3D electrical haulage shearer in working process caused by something hard, the paper did improvement analysis of the shearer and pointed out the best method is improving cutting axle. Then it proposed an improvement scheme of cutting axle, namely making a man-made thin point in cutting axle for damage when the drum cuts something hard so as to cut driving power, and making a screw hole in axle center so as to take broken axle out of the motor. The improved shearer has been applied in a fully-mechanized working face of Dongtan Coal Mine. The application showed that the improvement scheme greatly shortens replacement time of cutting axle, decreases fault rate of damage of ranging arm, and improves security of shearer mining.