Cooling and lubricating system of marine diesel engine

The invention discloses a cooling and lubricating system of a marine diesel engine. The cooling and lubricating system comprises a freshwater pump, a sea water pump and an engine oil pump, wherein the freshwater pump, the sea water pump and the engine oil pump are independently driven by alternating current motors respectively; rotary speeds and power of the freshwater pump and the sea water pump are adjusted according to temperatures of cooling water of the marine diesel engine; and rotary speeds and power of the engine oil pump are adjusted according to engine oil pressure of the marine diesel engine. With the adoption of the system, the power consumption of the whole machine can be greatly reduced, the fuel economy of the diesel engine is improved and the service life of the diesel engine also can be prolonged.