For the particularity of some departments' work and mission, the command and dispatch system based on TD-SCDMA network is proposed. Their needs for the point-to-point communication service and the group call service of the one-tomultipoint communication can be met in 3G mobile communication network. In view of the fact that people need this particular communication mode and the communication features of command and dispatch system, the centralized transmission network structure and the scattered transmission network structure of command and dispatch system based on TD-SCDMA network are given. At the same time, the communication protocols of the group call are discussed in detail. Finally, the command and dispatch system is simulated by using OPNET software. The result shows that the command and dispatch system can need the different stages of development and can reduce the blocking probability of leading to core network by adopting the rational network structure.