The dynamic behaviors of molten pool and keyhole have significant effects on the weld forming quality and mechanical performances of welded joints. In the process of induction-assisted oscillating laser welding, the oscillating laser beam has the stirring effect on the molten pool, which affects the heat transfer and flow behavior of the molten metal strongly. To investigate the dynamic behaviors of molten pool and keyhole in the induction-assisted oscillating laser welding, a multi-physics coupling numerical model is developed for the induction-assisted oscillating laser welding. In this paper, the characteristics of temperature field, flow field and electromagnetic field of the molten pool are obtained by the numerical calculation and the dynamic behaviors of molten pool and keyhole are discussed. Based on the numerical calculation results, it is found that the induced current density in the base material is gradually decreasing with the increase of the distance from the bottom of base material and the Joule heat generated by the induced current has a significant effect on the dynamic behaviors of molten pool and keyhole. Compared with the oscillating laser welding, the depth and width of molten pool increase and the stability of keyhole is improved in the induction-assisted oscillating laser welding, which is benefit for the pore defect reduction. The research in this paper show that the developed model is efficient for understanding the dynamic behaviors of molten pool and keyhole in the induction-assisted oscillating laser welding and hence improving the welding quality.