Abstract: The marine environment in coastal seas is threatened by ambient noise generated by offshore engineering such as wind farms. Taking Rudong sea area as the research area, and we divided the area into port area, wind farm area and fish migration area. The marine environmental noise of each area is monitored, and the underwater noise data and hydrometeorological elements are obtained. By calculating the ambient noise in each area, the power spectral density was analyzed for the noise spectrum and regional distribution characteristics. It was found that marine engineering caused a significant increase in the noise power spectrum at different frequencies in the Rudong sea area, and the peak value of the noise power spectrum also increased. The underwater noise in the port area below 140 Hz appeared shallower than the bottom layer, which was different from other areas. The extreme value of the noise power spectrum of the wind farm area increased the most. The noise power spectrum in the sea area of the fish migration area appeared more than 1000 Hz Peaks. The underwater noise in the sea area of the port area and the wind farm area presented a trend that the near-shore area was larger than the far-shore area. Marine engineering caused drastic changes in underwater noise in Rudong Sea. The main frequency of the noise was similar to the sensitive frequency band of some major marine organisms in the sea area. The noise power spectrum was critical or even exceeds its hearing threshold. This will interfere with the hearing and survival of marine organisms. As a result of death, there is an urgent need for long-term monitoring and control of the underwater environmental noise in Rudong Sea.