The invention discloses a multi-dimensional feature dynamic identity authentication method and a multi-dimensional feature dynamic identity authentication system for power business. The method comprises the steps of collecting time, space and behavior feature data of a to-be-authenticated user; based on the time, space and behavior feature data of the to-be-authenticated user, in combination witha pre-obtained feature frequent item set and confidence, performing consistency detection through a random forest classifier; and when the consistency detection is passed, performing identity authentication on the to-be-authenticated user based on the universal authentication framework. According to the invention, identity authentication is carried out based on three-dimensional characteristics oftime, space and behaviors by researching influence factors of power scene security authentication. Therefore, the security strength of power business identity authentication is effectively enhanced,and the authentication cost is reduced.