The invention provides an implementation method and system of a broadband digital cluster service, a cluster dispatching management center, a BM-SC, an MBMS-GW, an MME, an MCE, a base station, user equipment and a network side device. The implementation method of the broadband digital cluster service comprises the steps that (1) the cluster dispatching management center receives a cluster call establishment request; (2) the cluster dispatching management center sends a created cluster bearing request carrying calling information and a transmission bearing address to a network side according to the cluster call establishment request. Compared with a solution of a private network cluster communication system which is built on the basis of the second generation mobile communication technology, according to the technical scheme, the requirement for the broadband of the cluster service can be effectively met, and transmission efficiency is improved. In addition, the utilization rate of frequency resources can be improved, and application of a cluster communication service is expanded from a traditional private network to a mobile public network.