A method for controlling a power management system includes if a registration mode of a smart socket is performed in a power management apparatus, displaying a second code of the power management apparatus; acquiring a code image of the second code on the power management apparatus using a terminal acquiring a code image from a first code assigned to the smart socket to recognize each other; receiving information of an electric device to be coupled to the smart socket; and pairing the smart socket corresponding to the first code by reading the code image with the electric device information, transmitting the paired information to the power management apparatus corresponding to the second code, and storing the paired information in the power management apparatus corresponding to the displayed code.