The nitrogen content in the weld of high nitrogen steel is an important factor affecting its mechanical properties. It is a fact that mechanical properties of weld deteriorate with the decrease of nitrogen content in welding of high nitrogen steel. In order to solve this problem, the laser arc hybrid welding experiment was carried out on 12 mm thick high nitrogen steel plates, and the effect of nitrogen content on the microstructure and mechanical properties of weld was studied by changing filler materials. Results show that the use of nitrogen-containing welding wire can effectively supplement and the nitrogen loss in the weld. The nitrogen content of welding seam of nitrogen welding wire is higher in the laser zone, the nitrogen content of both welding wires increases with the increase of laser power. The weld microstructure of the two kinds of welding wires is austenite and a little ferrite. The tensile strength of stainless steel welding wire increases with the increase of laser power, and the tensile strength of nitrogen-containing welding wire first increases and then decreases with the increase of laser power. The maximum tensile strength reaches 953 MPa. The fracture surface of weld shows typical ductile fracture characteristics. The weld impact properties of the two kinds of welding wires are quite different, and the impact fracture has obvious ductile fracture characteristics.