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.