Abstract: For the process of laser cladding of multicomponent alloy, the model for heat and mass transfer of three-dimensional pool and solidification structure evolution were established based on the finite element method and cellular automata technology. The coupling of model for three-dimensional molten pool and model for multi-element alloy solidification structure evolution was realized by self-developed macro-micro coupling interface program. The heat and mass transfer and solidification structure evolution of IN718 laser cladding process were simulated. The effects of initial grain size, heterogeneous nucleation and scanning path of multilayer cladding on the solidification structure and morphology of cladding layer were investigated, and the simulation results were verified by experiments. The results showed that the simulation results were in good agreement with the actual physical process, and the developed coupling model truly reflected the laser cladding process of multicomponent alloys.