In order to analyze efficiency of electric-drive AMT shifting actuator from experimental perspective and form an effective test evaluation system，an average transmission efficiency test program is designed through analyzing features of electric-drive AMT shifting actuator. According to the motion law of electric-drive AMT shifting actuator，a new computing method of the average transmission efficiency is proposed. Based on the AMT actuator test bed，the average transmission efficiency of an AMT shifting actuator is respectively tested in two working conditions with time-constant load-variable and with time-variable load-constant. Results indicate that the average transmission efficiency on the basis of the test program and computing method have a good repeatability；and when the test time is constant，the average transmission efficiency increases along with the load；however，when the load is constant，different test time has little effect on the average transmission efficiency.