Due to the constraints of electromagnetic, mechanical and thermal, the design of highspeed permanent magnet motor with amorphous alloy core is an integrated process. Based on the method of multiphysics analysis, the influence of amorphous alloy to the motor was analyzed, the stress distribution of interior permanent magnet rotor was studied. Also, the influence of bearing stiffness for critical speed of rotor system was analyzed. In consider of the distribution of loss, thermal analysis was shown. Based on the method of integrated design, a highspeed permanent magnet motor with amorphous alloy core rated as 15 kW, 30 000 r/min was designed and fabricated. Through the test of the motor, the multiphysics field analysis and integrated design was proved feasible and the theory for the design of highspeed permanent magnet motor with amorphous alloy core was provided.