By using the ansoft software, Hiest has designed and researched HCTYC specific permanent magnet motor AOI of air compressor and HCTYP permanent magnet variable motors based on the special conditions of air compressor, to satisfy all operation conditions of air compressor. The special stator and rotor magnetic field can minimize the cogging torque, suppress the high-harmonic magnetic field, in order to satisfy the design indexes of broadband, energy conservation and low noise. It is featured by wide-range and constant-torque power regulation, stable speed regulation and has no torque ripple. The stator and rotor are made of high-performance low-loss silicon steel sheets, while the rotor magnetic steel is made of high-performance NdFeB permanent magnet material. The ultra-high intrinsic coercive field of permanent magnetic, can ensure higher resistance to demagnetization of permanent magnet, to prevent demagnetization of air compressor when running at high temperature.