The invention discloses a method, device and system for selecting a coordinated multi-point transmission set. Each main transmission point utilizes a first algorithm to respectively work out the energy efficiency of all candidate user devices of the main transmission point in a plurality of coordinated multi-point transmission sets according to the receiving intensity of reference signals sent by all the candidate user devices in the main transmission point to the main transmission point and other transmission points; a second algorithm is utilized for respectively working out the energy efficiency of service cells of the main transmission points in the multiple coordinated multi-point transmission sets of the main transmission points; the worked out energy efficiency of the service cells of the main transmission points in the multiple coordinated multi-point transmission sets on the main transmission points is sent to a center node so that the center node can utilize a third algorithm to determine at least one coordinated multi-point transmission set, and the determined coordinated multi-point transmission set is sent to the main transmission point corresponding to the determined coordinated multi-point transmission set; the high system energy efficiency can be achieved.