Abstract: The laser motion trajectory and energy distribution during the circular oscillating laser welding process of stainless steel thin plates were calculated using numerical methods, and the effects of oscillating frequency and oscillating amplitude on laser energy distribution were studied. The oscillating laser welding process experiments on 1Cr18Ni9Ti stainless steel sheets were conducted and the effects of oscillating frequency and oscillating amplitude on the morphology, surface quality, and mechanical properties of the weld seam were analyzed. The research results indicate that the oscillating amplitude has a significant impact on the laser energy distribution on the surface of thin plates. As the oscillating amplitude increases, the laser energy distribution in the weld seam tends to be uniform,with a significant decrease in energy peak and a decrease in temperature gradient, resulting in insufficient melting of the base material at the edge of the weld seam, hindering the flow of the molten pool, and forming local undercuts. The oscillating frequency has a significant impact on the energy distribution on both sides of the weld seam. At low oscillating frequencies, there is a significant asymmetric distribution of energy on both sides of the weld seam. As the oscillating frequency increases, the energy on both sides gradually becomes uniform. Circular oscillating laser welding can effectively improve the elongation after fracture of 1Cr18Ni9Ti welds.