Abstract: According to the characters of laser cladding, a computational model was established for analysis of 3D laser cladding temperature field caused by moving gauss distribution heat source and laser cladding temperature field of 6061 Al alloy was simulated dynamically by finite element method with software ANSYS.The results show that the isotherms of temperature field simulation look like ellipse and are dense at the head of the moving heat source.And the temperature gradient is high at the head of the moving heat source. But at the end of the moving heat source the isotherms are sparse and the temperature gradient is low.With continuous wave Nd:YAG laser, SiC ceramic powder was cladded on the 6061 Al alloy surface and the SiC reinforced metal matrix composites (MMC) modified layer was abtained.Al, SiC and Al₄C₃, and a little Al₄SiC₄were included in this layer.It was shown that the simulation results of temperature field are in accordance with the experimental results.It offers the reliance for the optimization of the laser parameters on metal matrix composites.