Abstract: Torch pose is very important in welding intersection line which is a kind of complex space curve and needs all position welding. The fuzzy control arithmetic for torch pose fitting on saddle-back coping intersection line welding robot was designed. Weld slope, weld rotation, size of groove, intersecting cylinder thickness and intersected cylinder thickness were input variables. Working angle and walking angle which are determinant factors in torch pose were output variables. A multiple-input multiple-output fuzzy controller was built, the subjection function of input variables was planned, fuzzy control principle was designed by experience induction, and the relevant rule table was built. In order to distinguish the influence on output variables with different input variables, method of weighted was employed in the fuzzy expert system. Torch working angle and walking angle were fitted. Simulation of different diameter cylinder was made. The result shows that the fuzzy control system can achieve torch pose fitting effectively.