The flow noise reduction of Al alloy model with low surface energy coatings have been studied in a water tunnel. The results are compared with measured previously an Al alloy model, large difference are formed between Al model and covered low surface energy coating, the flow noise of covered coating model were capable of decreasing 3～19dB in 1～1.6kHz. The surface structure of covered coating model contributed to its inhomogeneous components of laminar powder by increasing bond between water and coating to turbulent flow of the boundary layer and decreasing the eddy size of boundary layers.