The invention relates to a high-performance low-emission diesel engine. The high-performance low-emission diesel engine comprises a crankcase ventilation system, a cylinder cover, an air inlet and preheating system, a fuel system, a cylinder body, a lower box, a water pump and cooling system, a piston, a connecting rod, a crank, an oil pump, a lubricating system, an air exhaust and pressurization system, a belt, a gear train, a fuel injection system, a tail gas treatment system, a valve system and a timing transmission system. According to the technical scheme, the diesel engine is high in performance and low in emission.