Abstract:The greases used for submarine periscopes bearing should possess the comprehensive properties of wide temperature range, low starting torque, good corrosion protective performance and long service life according to the working condition of submarine periscopes bearing. A polyurea based grease can be used for submarine periscopes bearing was prepared, the effect of base oil, thickener structure and additive on the properties of grease was studied,and the composition of grease was optimized. The results show the mixture of two different synthetic hydrocarbon oils possesses both good high and low temperature performance and compatibility with thickener. The tetraurea prepared by hexanediamine and two different monoamines has excellent thickening performance, and the consistency can satisfy application requirements. The as prepared grease was compared with S 81 aluminum complex grease, indicating that it could satisfy the application requirement of submarine periscopes bearing.