The electromagnetic water heater consists of electromagnetic heating converter, sensors, casing, metal water pipe, magnetic ferrite strip, water pipe skeleton, heat conducting medium passage, electromagnetic coil, coil skeleton, reflux pipe, afterheat absorber, pump, screw propeller, heat sink, motor, great power transistor IGBT, circuit board, isolating board, LED panel, functional switch, etc. The present invention has optimal work performance of the electromagnetic elements, raised heat efficiency, no electromagnetic interference and other advantages.