The invention relates to a method and device for repairing indentation of a steel plate through electromagnetic induction heating. The device comprises an existing manipulator, an actuator is clampedat the tail end of the manipulator and comprises an actuator frame, a spiral disc-shaped working coil is arranged inside the lower end of the actuator frame, and the two ends of the working coil are connected with the positive and negative poles of a power supply for outputting a high-frequency current separately. The power supply provides the high-frequency current for the working coil, a high-frequency alternating magnetic field is generated by the high-frequency current, the dented steel plate is located in the high-frequency alternating magnetic field and cuts magnetic force lines which constitute the magnetic field, an eddy current is generated on the section perpendicular to the magnetic force lines, heat energy is generated by the eddy current and used for heating the dented steel plate, and the dented steel plate is partially, momently and quickly heated for repairing the indentation of the steel plate. The actuator is controlled by the manipulator to move so that the actuatorcan move along a designed repairing path, and repairing quality and precision are guaranteed. According to the method and device, design is reasonable, the repairing effect is good, and repairing efficiency is improved.