Abstract: Optimal design of submerged arc welding wire and slag selection of matching flux were adopted,content of alloy elements and trace elements was reasonably controlled and content of impurity elements was strictly restricted,through which the purity and uniformity of welding material was increased. Through the macroscopic test and microanalysis,the submerged arc welding material suitable for large thick wall and deep groove of hydrogenation reactor was successfully developed. And welding material had characteristics of -30 ℃ low temperature impact performance stability,excellent process performance and low brittle tendencies.