Abstract: When H-shaped steel is welded by induction welding technology, the induced current is gathered to the V-shaped angle area formed by H-shaped steel wing plate and web plate, and the wing plate and the edge of web plate are heated, and the welding is completed with the cooperation of extrusion rolls. Among them, the uniformity of V-shaped angle will directly affect the welding quality. Therefore, obtaining accurate morphology and evolution law of H-shaped steel induction heating 3D welding heat source is a prerequisite for improving the welding quality of H-shaped steel. A method of dynamic pointer assignment was used to simulate the dynamic induction heating of H-beam steel. The regularity of the electromagnetic field and temperature field in the welding zone of H-beam steel during dynamic induction heating was analyzed. The results show that the welding temperature length (1150-1450 ℃) of the web at V point of H-shaped steel is bigger than that of the wing plate under dynamic induction heating. The magnetic induction intensity and eddy current magnitude at the H-shaped steel wing plate are bigger than those at the web plate, and the sharp angle effect on each node of the web plate is small. The faster the heating welding speed, the lower the temperature at the V-shaped corner, but the temperature uniformity increases.Finally, the experimental validation was performed, and the feasibility of induction welding technology of H-shaped steel was verified by comparing the experimental data and simulated data of selected key points.