Multicast address allocation is a key and difficult points of HLA simulation system. Multicast address allocation need to select or improve according to the actual application needs. In the data distribution management based HLA simulation grid, for the contradiction of redundant data receives and multicast address demand , we put forward a multicast address allocation of HLA hierarchy structure and described the data forwarding algorithm. Within the site, multicast address allocation use the method based on the data receiver and forwarding server contains a filter allocation table based on the receiver's multicast address.When there is a data access, RTIA according to assign tables to forward the data to the appropriate multicast addresses. Using this method, you can avoid node receives data not related to.The simulation experiment and results analysis show that: the maximum level of nodes in the multicast reception of the message overhead can be significantly enhanced; using the hierarchical multicast routing aggregation, and based on the aggregation of routing information that is both feasible and effective.