Abstract: To study the effect of marine microorganisms on the corrosion of typical metal materials for marine engineering in service and the corresponding mechanism, the corrosion behaviors of the three alloys including 316 stainless steel, 2024 aluminum alloy and TC4 titanium alloy in seawater solution containing chlorella vulgaris were studied separately.The results show that there is a significant difference in the corrosion behavior of the three alloys in dynamic seawater containing chlorella vulgaris. After 14 d of washout test, the corrosion resistance of both 316 stainless steel and TC4 titanium alloy is better than that of 2024 aluminum alloy. The surface corrosion products and biofilms of 316 stainless steel and TC4 titanium alloy are relatively fewer, and it doesn’t form a large amount of accumulation of corrosion products, and the passivation film on the surface of the matrix is not completely destroyed. The biofilm formed by chlorella attachment and the corrosion product membrane of the sample can play a certain protective role on the metal matrix and reduce the corrosion rate of the metal. However, with the continuous extension of the soaking time, the biofilm on the surface of the sample gradually falls off, and the corrosion rate of the metal materials is accelerated. The long-term stability of the protective film on the surface of TC4 titanium alloy is good, and the corrosion rate of 316 stainless steel is comparatively lower and the corrosion resistance is better.