A secure transmission method for broadband wireless multimedia network broadcasting communication includes the following steps: a secure channel between big base station and small base station is established by utilizing security protocols; the big base station distributes a Broadcast Traffic Encryption Key to each small base station through the secure channel; the small base station transmits the Broadcast Traffic Encryption Key to the user passing the authentication and authorization. The above solution solves the problem of broadcast secure communication of the big base station working in the mixed covering mode of large and small cells, realizes the identification of not only the user but also the base station, and ensures that only the authorized user can receive broadcast service.