Embodiments of the present invention provide a method and a device for associating a user with a group. The method includes: receiving, by a first communications device, a first association request sent by a second communications device, where the first association request includes an identifier of an MCPTT user and identifiers of N MCPTT groups, and N is a positive integer; associating the MCPTT user with M MCPTT groups of the N MCPTT groups according to association subscription information of the MCPTT user; and sending a first association response to the second communications device, where the first association response is used to indicate that the MCPTT user is successfully associated with the M MCPTT groups of the N MCPTT groups, 1≤M≤N, and M is an integer. In this way, the MCPTT user is associated with the M MCPTT groups that the MCPTT user is interested in.