Abstract: The welding seam of intersecting pipes is typical and complicated space welding seam.A new welding robot with 5-degree of freedoms robot is designed with the mixed method of series and parallel for special welding technological requirements of welding seam of intersecting pipes,which realized the one integrated design of organization for robot anchor,motion mechanism,welding gun adjusting mechanism and wire feeder.An automatic centering robot trick with 2-degree of freedom is designed,which realized control to gun position and pose separately.The kinematics model of the welding robot is build,and the real-time control mathematical model of welding gun position,welding gun pose and welding speed is build too for the general welding seam of intersection.The welding result indicates that the anchor is secure and accurate,the controllability during the welding is good,and the control method can satisfy the technological requirement of welding seam of intersection.