The multi-physics simulation of laser melt injection process is conducted and the effects of electromagnetic compound field parameters on the distributions of the flow field, temperature field and particles within the molten pools are investigated, which is also verified by the experiment. The results indicate that, the addition of the electromagnetic compound field can suppress the fluid speed, but does not obviously influence the temperature field distribution. When the directional Lorentz force and the gravity force are in the same direction, the majority of reinforcement particles is trapped in the upper region of the laser melt injection layer, conversely, the majority is in the bottom region.