Abstract: Laser cladding was used to prepare Fe314 alloy powders cladding layer on EA4T steel, and the effects of heat treatment temperature on the microstructure and mechanical properties of the cladding layer were explored. The results show that the crystal morphology of the cladding layer does not change before and after the heat preservation treatment at 350 ℃.The dendrite chains of the cladding layer are broken after the heat preservation treatment at 550 ℃ to form rod-shaped crystals and the network structure is reduced. The cladding layer is composed of austenite, interdendritic carbides and Cr B. Heat treatment only changes the crystal morphology and does not change the phase composition. Under the action of heat treatment,the hardness of the cladding layer and the substrate decreases and the cladding layer is closer to the substrate microhardness,the hardness distribution of the matrix becomes more uniform. The residual stress of the cladding layer and the matrix part reduce, and the tensile stress in the cladding layer is transformed into compressive stress. The impact resistance of the cladding sample is increased by about 1.9 times, and the fracture mode changes from brittle fracture to a mixed fracture in which ductile fracture and brittle fracture coexist.