The electromagnetic heater system of 8kw granulator first rectifies 380V, 50 μ 60Hz AC into DC, and then converts DC into high-frequency high-voltage power with frequency of 8-20kHz. When the high-frequency high-voltage current with high-speed change flows through the coil, it will produce an alternating magnetic field with high-speed change. When the magnetic force line in the magnetic field passes through the magnetic metal material, it will produce countless small eddy currents in the metal body, making the metal material itself heat at high speed, so as to achieve the purpose of heating the material in the metal barrel.