Abstract: In vehicle maintenance works, roller type dynamometers or acceleration testers are used to measure the vehicle power. Both of the two kinds of equipment are not very popular for some reasons: the dynamometers are expensive and the acceleration testing rig usually with a little shortcoming, such as in accuracy and the unknown rotation ineria. A partial load acceleration power test method which will improve the performance and keep the lower price was developed. It is suitable and helpful for more vehicle maintenance works.