Abstract: In order to verify the feasibility of laser-plasma arc composite deposition process, the 316L block specimen was manufactured by plasma arc additive manufacturing firstly, then by the laser melting deposition process on the first formed matrix.By using optical microscope, scanning electron microscope, microhardness tester, tensile testing machine and other methods, the macro-morphology, microstructure characteristics, mechanical properties, fracture morphology of different deposition positions were studied.The results show that the thickness of the plasma arc deposition layer is more than 3 times of that of the laser deposition layer. The microstructure of the plasma arc deposition layer is significantly coarsened, and the secondary dendrites are developed.The hardness of the laser deposition layer is higher than that of the plasma arc deposition layer. The deposition layers by the two processes have formed a good metallurgical combination. The thickness of the interface heat affected zone is less than 100 μm.Although the laser plasma arc composite process can achieve the composite deposition forming of 316L sample, and it has certain advantages in deposition efficiency compared with the plasma arc deposition process, the strength and elongation of the composite processing sample are lower than those of the plasma arc deposition sample.