Abstract: Aiming at the problems of little ability of current carrying,simple protection, high fault rate of flameproof switch for underground 6 kV power grid,the paper proposed a design scheme of integrated protection system of high-voltage flameproof switch based on multi-CPU control,analyzed working(principle) of fault protection of 6 kV high-voltage power grid of coal mine underground,and introduced(design) of hardware and software of the system in details.The integrated protection system of high-voltage flameproof switch based on multi-CPU control used(single-chip) microcomputer MSP430F149 and DSP TMS320VC5402 as main controllers,and the main(controllers) synthetically analyzed all kinds of signals of power grid in order to realize function of general monitoring for high-voltage power grid.The experiment(result) showed that the system is stable in running,reliable in action and accurate in display.