When the electromagnetic waves propagate over the sea surface, there exists reflection, scattering and diffraction. Impact of sea clutter to the communication link is an important issue to evaluate and demonstrate. In this paper, we simulate the communication transmitter and receiver and use the theory of random bridge to build a random multipath channel model of the sea surface. Combined with typical DSSS/BPSK modulation, we analyze the downstream communication link model and calculate the performance of communication system, which is obtained under typical sea conditions, grazing angle and distance. As a conclusion, the results indicated that the impact of sea clutter to communication link is not very significant.