IE4 super premium efficiency IEC60034-30-1:2014 issued by IEC the highest efficiency level of the motor in the standard. The B method was used to measure the input and output power loss analysis method to test the large loss of the YE4 series (IP55) three phase asynchronous motor, and to verify the effect of different consumption design measures. Thus, the whole series motor had reached the level of IE4 efficiency level. The successful development and application of YE4 products would made an important contribution to further promoting the implementation of China’s energy saving and emission reduction policies.