Broadband trunking communication system is a specialized command and scheduling system for mobile communication, which has characteristics such as resources and costs sharing, high-efficient command and scheduling capability and so on. This paper firstly describes the evolution of broadband trunking communication. Based on the study of the system architecture and existing technologies, this paper proposes a way of simplifying the system architecture and elaborates the system framework into four modules including scheduler, server, base station and terminal. In the end, a program of broadband trunking communication server subsystem is designed and realized for voice service based on Linux platform. The results demonstrate the program has advantages of low-delay and high-efficient scheduling capability.