In order to study the effect of electromagnetic stirring on laser melt pool solidification of TA15 titanium alloy, A MHD mathematical model was established on minimal melt pool under the three-phase three-pole rotating electromagnetic stirrer. This model was used to calculate magnetic induction intensity in the center of magnetic field and the melt circumferential flow velocity in melt pool under different exciting current. The influence of circumferential flow velocity on temperature field and solidification structure formation were analyzed. At last the analysis results were verified by experiment method. The results showed that the electromagnetic force drived melt to flow circumferentially. Farer from the magnetic field center, lorentz force was larger which promoted the circumferential flow velocity of melt. Magnetic induction intensity was rising with the increase of exciting current, which caused more faster circumferential flow velocity. The enhance of flow velocity resulted in temperature going down in melt pool and temperature gradient on solid-liquid interface, which were good for generation of the equiaxed crystal. The experiment results testified that equiaxed grains were generated at the top of melt layer with the magnetic field. The number of the equiaxed grains were rising with an increase of the distance from magnetic field center. The tendency of analysis results are in good agreement with the experimental results.