The design of a 3 MW low-noise compact cage asynchronous wind power generator is performed aiming at the development trends of cage generator including high efficiency, low noise and high power density. The calculation process of the electromagnetic and cooling schemes of the cage generator is explained. The additional loss of rotor bar caused by the air gap magnetic field is reduced by electromagnetic simulation, and the ventilation noise is calculated by fluid simulation. The design is validated with type tests. The results show that the design method is feasible and the motor has a good performance.