Marine cylinder lubricant composition

The invention relates to a marine cylinder lubricant composition. The cylinder lubricant composition comprises, by weight, 5-10% of an ultra-high base number sulphonate clearing agent, 3-8% of an ultra-high base number phenate clearing agent, 4-10% of an ultra-high base number naphthenate clearing agent, 0.5-2.5% of a dispersing agent, 0.5-1.5% of an antiwear agent, 40-60% of high viscosity indexClass I base oil 400SN/500SN/650SN or high viscosity index Class II base oil 400SN/500SN/650SN and 10-35% of Class I high viscosity index base oil HVIS 150BS. A method of compounding three clearing agents is adopted, so that respective outstanding advantages of the three clearing agents are utilized, defects of the three clearing agents are also made up, the comprehensive lubrication performance of marine lubricating oil is improved, and requirements of novel marine engines for lubricant performance can be met. Based on the premise that the composition is adapted to the traditional Class I base oil, the composition is compatible with the Class II base oil and is not restrained by base oil supply. The composition passes the original equipment manufacturer (OEM) authentication.