<p>By constructing three inter-related models and employing indirect coupling techniques, an in-depth analysis of the molten pool formation mechanism and its dimensional features during the laser cladding process was carried out. The first model is a comprehensive laser cladding model that reveals the genesis and geometric structure of the molten pool; the second is a molten pool model that incorporates UDF boundary conditions to analyze the flow and temperature distribution within the pool; and the third is a coupling model of the molten pool and substrate unit based on mapped boundary conditions, aimed to study the residual stress field within the molten pool. These models together form an integrated system simulating the interactions of flow, thermal transfer, and mechanics within the molten pool, and the simulation results were validated and calibrated against experimental data. The study discovered that the movement of the laser heat source causes uneven heat flux diffusion, leading to a wider rear part of the molten pool compared to the front. In the direction of heat source movement, the molten material predominantly flows from front to back, creating a series of metal ripples extending in the opposite direction. The molten pool model that accounts for turbulence effects shows a reduced maximum temperature, and a groove-shaped temperature distribution appears at the bottom of the pool. Additionally, the residual stress in the bonding zone between the molten pool and the substrate is most pronounced, making it a high-risk area for crack formation.</p>