In order to solve the problem that the lubricating oil cannot be delivered to the surface of each friction pair in time during the engine start-up process, and severe wear occurs in a short period of time in the state of boundary friction or solid dry friction lubrication, the integrated pre-lubricated oil pump assembly driven by the air motor is designed as a solution. Relying on the engine lubrication system test bench, by changing the initial state of the lubrication system (lean oil or rich oil) and the air intake pressure of the air motor, the pre-lubrication process and the cold start process of the engine were tested and studied. The results show that the integrated pre-lubricated engine oil pump can quickly establish a stable oil pressure of more than 1 bar in the main oil passage when the intake pressure is 2~6 bar; When the intake pressure is 3 bar, the time for the oil pressure of the main oil passage to reach the calibration oil pressure is 7~8 s ahead of time when the engine is cold started. It can be seen that the integrated pre-lubrication oil pump assembly can effectively perform engine start-up pre-lubrication, and avoid wear caused by solid dry friction of bearings and other moving friction pairs during the cold start of the engine.