In view of the problem of testing the mechanical state of transformer, a method of testing the state of transformer winding and iron core machinery based on the energy index of the IMF is proposed. According to the energy characteristics of IMF, a binary feature vector based on IMF index energy is established. The variation of the characteristic vector of transformer vibration signal based on the index energy under the condition of normal state and fault state is compared by experimental. The results show that the characteristic vector of transformer vibration signal based on index energy changes obviously before and after the fault occurs, and the mechanical state of transformer can be detected according to the characteristic vector.