Abstract: By using the measuring method of superficial sound pressure level and the atmospheric press-ure simulation equipment,and taking the 4100QBZL diesel engine as the research object,the sound power levels on the surface of the turbo-charged diesel engine in the cases of the same rotational speed with different altitudes,different altitudes with different rotational speeds and different advance angles of fuel supply with different rotational speeds are tested and calculated.The analysis of test results indicate that,the surface-radiated noise increases with the rotational speed increase;At the same rotational speed,the noise of the turbo-charged diesel engine increases with the altitude increase,and varies with the advance angles of fuel supply.