Diesel engine and oil supply system thereof

The utility model discloses a diesel engine and an oil supply system of the diesel engine. A high-pressure oil pump and an oil injector in the oil supply system are both communicated with an oil rail, the generating process of injection pressure is completely separated from the injection process, high-pressure fuel oil is delivered to the oil rail through the high-pressure oil pump, accurate control is achieved through oil pressure in the oil rail, the pressure of an oil pipe is made independent of the rotating speed of the engine, the degree of change of the oil supply pressure of the diesel engine along with the change of the rotating speed of the engine can be lowered greatly, in this way, the oil supply system can continuously and stably supply well atomized fuel oil to the engine, and exhaust emission of the diesel engine with the oil supply system can reach a higher standard.