The utility model relates to a coal mill bearing lubrication system, and aims to solve the problems that in the prior art, when a coal mill bearing lubrication system operates, owing to long operating time of an oil pump, mechanical wear is high, oil amount is adjusted frequently, since oil excess, oil lack or oil finish occur often, bearings can be burnt, equipment can be damaged, environment and safe production can be influenced, owing to large on-site noises, much dust and poor environment, staff on site can be physically and mentally damaged, and working efficiency is low. The lubrication system comprises a sponge member, a high level oil tank, an oil pump, a limit contact device, a float, a shaft, a low level oil tank, a first oil inlet pipe, a second oil inlet pipe, a first oil outlet pipe, a second oil outlet pipe, an oil return pipe, a spiral adjusting rod, a pressing plate, two bearing seats with bearings, two level meters and two level control boxes. The system is adaptable to a coal mill bearing lubrication system.