After　welding,　there　is　a　large　residual　tensile　stress　at　the　welding　place,　which　must　be　eliminated　in　time;　otherwise　it　may　have　a　significant　impact　on　the　later　use　of　the　equipment.　In　this　paper,　1Cr5Mo　steel　was　used　as　the　object　of　study　to　discuss　the　effect　of　post-weld　heat　treatment　on　its　residual　stress.　The　residual　stress　was　obtained　by　different　heat　treatment.　The　mechanical　properties　and　stress　corrosion　resistance　of　the　specimen　were　studied　under　the　combined　residual　action,　and　they　also　had　corrosive　medium　performance　changes　in　the　law.　It　is　found　that　the　effect　of　tempering　treatment　on　the　residual　welding　stress　is　obvious.　The　residual　stress　has　a　significant　effect　on　the　stress　corrosion　resistance　of　the　specimen,　and　the　higher　residual　tensile　stress　can　cause　the　high　temperature　and　corrosion　resistance　of　the　sample　which　need　to　be　greatly　reduced.　This　conclusion　can　provide　valuable　preventive　measures　for　the　improvement　of　service　performance　and　life　of　1Cr5Mo　steel　equipment.