Abstract: ABAQUS software was used to simulate the single-pass multilayer laser metal deposition (LMD) of 316L stainless steel under unidirectional scanning (US) and reciprocating scanning (RS) strategies, respectively. Multiple physical field simulations were used to study the distribution of the temperature field of the thin-walled parts and the trend of the maximum temperature gradient in each layer, and the effects of residual stress on the deformation of critical areas of thin-walled parts in stress and deformation fields were investigated. Relevant experiments were designed to verify the results of numerical simulations and the relative errors between experiments and simulation under the two scanning strategies are 4.5% and 4.0%, respectively. The results show that the melt pool temperature increases layer by layer under both scanning strategies, especially the thermal accumulation effect of RS is more prominent. Along the layer height direction, the maximum temperature gradient values of each layer of US are larger than those of RS, and US is prone to tensile plastic deformation on the side of the starting point of thin-walled parts. Along the scanning direction, the difference in the maximum temperature gradient between RS and US increases significantly with the increase in the number of LMD layers, and RS is more likely to produce compressive plastic deformation at the top of the thin-walled part and tensile plastic deformation at the bottom. The overall morphology of the single-pass multilayer thin-walled parts further illustrates the accuracy of the LMD numerical simulation.