A method for a terminal to join a multicast broadcast service (MBS) in a wireless network and a wireless communication system are provided, so as to enable a terminal to successfully join an MBS and receive MBS content. The method and the system relate to a wireless communication field. A terminal obtains MBS parameters that include a first ID indicating an air interface connection and a second ID indicating MBS content from a network, so that the terminal can receive the MBS content indicated by the second ID from the air interface connection indicated by the first ID after receiving the MBS parameters and thus successfully join the MBS. The terminal may initiate an MBS join process by sending an MBS join request message, so as to obtain the MBS parameters and join the required MBS. The network may actively initiate the MBS join process to send the MBS parameters to the terminal and invite the terminal to join the MBS.