The source of aerodynamic noise of aircooled motor, the measurement method and the commonly used aerodynamic noise control measures in engineering were introduced. Taking an aircooled motor as an example, the steadystate flow field, the transient flow field and the sound field in the external wind path were numerically analyzed by CFD method, and the calculation results were verified by experiments. The reference significance for the aerodynamic noise analysis of selfventilated aircooled motor was prorided.