Abstract: This paper focuses on the mathematical model of weapon Fire-control-system simulator. A new scheme for designing the weapon fire-control-system simulator with single chip microcomputer is proposed. The single chip microcomputer controller takes charge of processing position & velocity data, limitation data and keystroke identification. The single chip microcomputer monitor is to detect failure protection signals and transfer them to IPC. The idea of modularization design is adopted in the single chip microcomputer software. The experimental results show that this weapon fire-control-system simulator achieves a high control precision with easy operations and perfect functions. This simulator has completed many key simulation tasks for many kinds of Weapon Fire-control-system..