Abstract: In view of problem that cutting section will take place error when pose of boom-type roadheader has error and will influence on directional mining seriously, the paper proposed a method that controlling cutting arm to make automatic compensation for cutting section. It analyzed control principle of rotary and lifting swing of cutting arm, built a combined model of rotary and lifting of cutting arm, and gave Matlab simulation verification of the model and application method of boundary compensation of cutting section by controlling cutting arm. The simulation result validated correctness of the method.