In order to solve the problems of part of the power waste and difficulty in selection of the excitation equipment in the blade fatigue loading method, a new direct-drive fatigue loading method was proposed, and the centrifugal, reciprocating and reciprocating methods were established by Lagrange method., and the required parameters of the equipment in each loading method was analyzed, and the relationship between the power of the equipment in each loading mode was established, and the power ratio coefficient was proposed to obtain the relationship between the maximum power required by the equipment in each loading method and the blade resonance power. The results show that the maximum excitation power of the three loading methods can be quickly obtained through the power ratio coefficient and the necessary resonance power of the blade, and the calculation error is less than 2.7%. The direct drive loading method requires less power and energy consumption than the other two loading methods. In the blade fatigue test, the testers can preferentially select the direct drive resonance loading method according to the actual test scenario.