Abstract: The attrition problem about the cupreous block of the AMT used on a prototype vehicle was put forward. The working principle of the shifting machine was analyzed. The shifting machine was refitted by mechanical sensor. After shifting force test on the AMT test-bed and the manual shifting on the vehicle, the reason of the attrition problem was located. Then, the control strategy of shifting was amended. Test on the AMT test-bed and the prototype vehicle with AMT proves that the improved control strategy is effective to solve the problem of attrition.