The forming mechanism and hazards of lubricating oil varnish were analyzed.The principle of varnish removal by the combination of charge adsorption filtration and exchange resin was introduced.The oil filter based on this principle was applied on the varnish removal of the gas turbine lubricating oil of offshore platform.The result shows that the varnish removal method and oil filter equipment of charge adsorption filtration and exchange resin can recover the unqualified lubricating oil tested by MPC to the qualified range,can improve and eliminate the instability of lubricating oil system caused by varnish.The method and the equipment have good effect on improving the cleanliness of the oil and removing the fine pollutants.