The invention discloses a motor shaft with an insulating ceramic, which comprises a shaft body, an annular groove is formed in the outer ring of the shaft body, and an annular insulating ceramic layerwith the thickness of 0.012-0.015 mm is covered in the groove. The invention discloses a preparation method of the motor shaft with the insulating ceramic, which comprises the following steps: ball-milling and mixing alumina powder, composite basalt fiber, zirconium dioxide, cerium dioxide, polyvinyl butyral, a flexibilizer, a densifier, a refiner and a tackifier until the particle size is less than or equal to 0.1 mu m, and drying at 105-112 DEG C to obtain a premix; derusting and descaling the surface of a shaft body through a grinding wheel to be smooth and clean, then polishing the shaftbody through abrasive paper, removing greasy dirt with acetone, pickling with hydrochloric acid, washing with ethanol, and drying to obtain a pretreated shaft body; and electroplating the premix to the surface of the pretreated shaft body, accurately grinding until the coating thickness is 0.012-0.015 mm, and polishing to obtain the motor shaft with the insulating ceramic.