The invention discloses a coal gas concentration monitoring system based on a single chip microprocessor. The coal gas concentration monitoring system based on the single chip microprocessor is characterized by comprising the single chip microprocessor, a power supply, a crystal oscillator circuit, a reset circuit, an EPROM (erasable programmable read only memory), a communication interface module, a sound-light alarming module, a coal gas monitoring module, a display module, a keyboard, a program operation monitoring system and an execution circuit module, wherein the single chip microprocessor is respectively connected with the power supply, the crystal oscillator circuit, the reset circuit, the EPROM, the communication interface module, the sound-light alarming module, the gas monitoring module, the display module, the keyboard, the program operation monitoring system and the execution circuit module, the coal gas monitoring module is used for monitoring a coal gas value in the air of a target unit and transmitting the monitored coal gas value to the single chip microprocessor, and the execution circuit module can reduce or lower the coal gas value in the air by controlling the physical state of the target unit. The coal gas concentration monitoring system based on the single chip microprocessor has beneficial effects of low cost, capability of completely and intelligently monitoring and controlling the coal gas concentration, easiness in development and convenience in large-scale popularization and application.