For an aero turbo-shaft engine, rain water enters the intake protection device and the morphology of water droplets after hitting the wall will affect the internal flow of the compressor. In this paper, Sommerfeld number was used to determine the shape of water droplets after they hit the wall. The flow field and characteristics of the compressor with inlet particle separator under different water ingestion conditions were studied with considering the impact of water film and droplets splashing near the wall. The results show that the entry of water droplets deteriorates the internal flow field of the compression component, and the water film affects the flow state of the airflow near the wall. Compared to the effect of the splashing factor, the viscous resistance effect of water film near the wall on the airflow and boundary layer can cause a significant reduction in the characteristics and stability of the compressor.