This paper focuses on the quantitative analysis and prediction on the impact of suspended sediment to the inshore water quality during Zhuhai port LNG channel dredging and construction process. To fully understand the distribution of inshore tidal current, on the basis of the inspection on the hydrological characteristics of the project sea area and its nearby waters, combining with the data from the test flow and tide gauge stations, as well as information on the preliminary work, this paper uses a numerical simulation method to simulate and calculates the state of tidal current field of the project sea area and its nearby waters, and reproduces its movement and characteristics. On the basis of the simulation of tidal current field, this model will predict the transport and diffusion of the suspension and be used to analyze the impact to the inshore water quality during construction.