As the use of clean energy increasingly gains attention, China's offshore wind power industry has been developing rapidly in recent years. However, the underwater noise from the wind power station has not been studied in our country while the noise from human activities as an environmental issue has attracted much concern around the world in the last few years. In this study, we collected the operational noise data from the offshore wind turbines in the vicinity of the Shanghai Donghai Bridge and studied the characteristics of different wind turbines. We compared the noise data from different depths of water, as well as compared the data collected by using different measurement methods. The results show that the noise data from each single wind turbine shares the characteristics of low frequency and low sound pressure level:the main frequency range is within 400 Hz and the sound pressure level is between 81 dB and 101 dB. The characteristics of underwater noise from different depths are basically the same when seawater flowing speed keeps constant, but when the speed increased, some of the main frequency lost or shifted. The fixed-point method we used can measure any location we set, but the measurement time is limited. Drift method can measure at any time but the measurement line is limited.