Abstract: A combustible gas alarm system with multipoint control unit (MCU) as the core is designed for integrated practice course of MCU and embedded system. The system has the function of sound and light alarm, automatic ventilation, dialing preset telephone and SMS sending. With the system working, when the gas sensor detects that the concentration of combustible gas exceeds the set value, the LED will flash and the buzzer will give an alarm. At the same time, the exhaust fan will be turned on to evacuate the combustible gas. When there is no one to deal with it beyond the set time, the preset mobile phone number will be automatically dialed through the communication module and the SMS will be sent to give a prompt to avoid serious accidents such as fire and explosion. Through close integration with practical applications, this project integrates multiple knowledge points, cultivates students’ learning initiative and creativity, and the effect of practical teaching is good.