Abstract: The effect of welding on the enamel of the welded joint of porcelain pipe was studied and a new method of self-deposition protection method was put forward to protect the welded joints of porcelain pipe.The results show that the enamel near the weld can remelt and flow to the weld and cover the weld metal when tungsten inert-gas(TIG) welding is used to backing weld with proper the current.Pre-brushing the enamel near the end of pipe before welding can add the thickness of the self-deposition enamel and improve the protection effect.Using flame to remelt the enamel on the welded joints after welding and cooling slowly can re-intenerate the enamel and remove the cracks and air bubbles in the enamel.Using the methods of brushing enamel before welding,backing welding by TIG,filling by shield metal arc welding and remelting enamel on the welded joints by flame can effectively protect the welded joints of porcelain pipe without internal repairing after welding.