The invention discloses an electric meter plug-and-play method based on random back-off, and belongs to the technical field of electric power. An existing automatic meter reading technology adopts a step-by-step matching polling meter searching algorithm, a large number of invalid meter searching operations exist, the average meter searching time is long, and the problem of incomplete searching exists. According to the invention, a plurality of parallel registration time slots are provided in one registration command period, the electric meter can select one from a plurality of different timeslots to send the registration request, the electric meter registration efficiency is greatly improved, conflict nodes are subjected to effective conflict decomposition in the case of conflict, and aregistration confirmation mechanism is provided in the case of registration to improve the registration reliability; Experimental verification and analysis show that compared with an existing registration mechanism based on the DL/T645 protocol, the method provided by the invention can effectively improve the efficiency of electric meter registration in an electric power acquisition system, shorten the registration time and improve the reliability of electric meter registration.