Poor lubrication between the ship's propeller shaft and the bearing causes serious wear and abnormal noise, which brings dangers to its reliability and stealth. In this paper, polytetrafluoroethylene (PTFE) and polyoxymethylene (POM) plastics with different surface wettability were selected to conduct ring-block friction tests under six working conditions in water environment to analyze their tribological characteristics. The vibration signal is collected by a friction test device with a high-precision vibration acceleration sensor, and the signal characteristics are enhanced by wavelet packet decomposition and reorganization. The molecular structure of the friction surface of the material before and after the test was characterized by the Raman Spectrum. The results show that the specific wear rate of PTFE under high load changes linearly with the increase of speed, while the POM shows a significant exponential change. There is no chemical change on the surface of materials after friction, and the copper rings are not scratched and transferred to the surface of materials.Compared with PTFE, the friction-induced vibration of POM is more severe at low speed and slighter at high speed. When the speed reaches 1000 rpm, the stable water film exists on surface of POM, which shows good water lubrication.