The uniformity of the magnetic induction intensity distribution of the electromagnetic heating in vulcanizing machine was studied. The analysis of the finite element model showed that，there was a dead heating zone in the center of the hot plate during the heating progress of the coil induction heating device. By adding a
circular iron core in the center of the coil，the uniformity of the magnetic induction intensity and temperature field distribution on the hot plate were improved，and the rubber vulcanization quality was improved.
