Abstract: A laser welding method was used to conduct welding experiments on A286 iron-based superalloy thin plates and the welded joints were subjected to heat heatment with 982℃ solid solution, and 982℃ solid solution+718℃ aging. The influence of heat treatment on the microstructure and mechanical properties of welded joints was studied. The results show that the weld structure of the welded joint was mainly composed of austenite, δ ferrite and γ' phases without heat heatment. After solid solution, the δ ferrite content in the joint weld increased, and the number of γ' phases decreased; the strength and hardness of the joint changed little, compared with those at weld state, but the elongation after the fracture increased from 17.3% at the weld state to 22.7%. After solid solution+aging, most of the δ ferrite in the joint weld structure was converted to austenite, whose grains were coarsened; a large number of diffuse distribution γ' phases were precipitated, and the tensile strength and yield strength of the welded joint increased from 639, 360 MPa at solid solution state to 1 019, 662 MPa; the average hardness reached 200% of solid solution state, but the elongation after the fracture was reduced to 17.1%.