1. An apparatus for recommending an electricity consumption behavior, comprising: a storage unit, being stored with an appliance efficiency value and an electricity-consuming parameter value for each of a plurality of users; and a processing unit electrically connected to the storage unit, being configured to generate a plurality of first temporary values by multiplying the appliance efficiency value of each of the users with the electricity-consuming parameter value of each of the users individually, generate a power saving matrix by using the first temporary values, generate a plurality of second temporary values by subtracting the electricity-consuming parameter value of each of the users from the electricity-consuming parameter value of each of the users individually, generate a changing willingness matrix by using the second temporary values, calculate a transform probability matrix by using the power saving matrix and the changing willingness matrix, calculate an eigenvalue and an eigenvector of the transform probability matrix, and recommend an electricity consumption behavior according to the eigenvalue and the eigenvector.