In this paper, high-throughput sequencing technology was adopted to visualize the microbial communities on the surfaces of two types of carbon steels immersed in Nansha waters. The results showed that different microbial communities were formed on different carbon steel surfaces, in which the genus with the highest abundance on the surface of Q235 was Escherichia-Shigella, while anaerobic Desulfovibrio on the surface of 921a was the most, and the dominant genus varied with the depth of the rust layer. In addition, the distribution of sulfate-reducing bacteria on the surface of Q235 submerged in Sanya waters conducted the environmental factors correlation analysis with the sulfate-reducing bacteria's distribution in Nansha waters. The results showed that the concentrations of Ca2+, Na+, K+, Mg2+ and Al3+ were positively correlated with the distribution of SRB, while the concentrations of Cu2+, Zn2+, SO42-, Cl-, NO3- and organic carbon were negatively correlated with it. Furthermore, there was a highly significant correlation between each geochemical factor and Desulfotomaculum (p<0.01).