An electric grinder with a switched reluctance motor comprises a body, a transmission assembly, a grinding wheel, and a dust-proof assembly. The body includes a first casing and a second casing. The transmission assembly includes a switched reluctance motor disposed in the first casing, a driving module disposed in the second casing, a transmission shaft connected with the switched reluctance motor, and an assemblage seat disposed in the transmission shaft. The assemblage seat includes an assemblage member for assembling the grinding wheel. The dust-proof assembly includes a dust-proof hood disposed in the first casing. Because of being driven by the switched reluctance motor, the electric grinder of the present invention adapts to the cases of phase failure, frequent start-stop operations, and phase inversion.