Diesel engine friction and accessory loss measurement method and device

The invention discloses a diesel engine friction and accessory loss measurement method, belongs to the technical field of engine friction loss detection, and mainly solves the technical problem that the existing detecting method is poor in precision. The method specifically comprises the following steps: controlling the gas intake pressure of a diesel engine and motoring the diesel engine to operate to make the diesel engine simulate normal work, and obtaining motoring power; measuring the in-cylinder pressure in gas intaking and exhausting processes when the diesel engine operates in real time; if the in-cylinder pressure is greater than a threshold value, calculating indicated power in pure compressing and pure expanding processes according to a polytropic equation of thermodynamics; otherwise, obtaining a cylinder pressure curve in the gas intaking and exhausting processes according to the in-cylinder pressure, and performing integrating on the cylinder pressure curve to obtain pumpgas loss power; and obta