A first network device receives a group selection request, where the group selection request is used to instruct to set a first MCPTT group as a selected MCPTT group for a first MCPTT user; and the first network device sends, according to the group selection request, information about the first MCPTT group to first UE used by the first MCPTT user, so that the first network device can set the first MCPTT group as a selected MCPTT group for the first MCPTT user.