The invention discloses a self-adaptive infrared system for monitoring the internal environment of an automobile, comprising sensors, an ECU (electronic control unit) system, a signal processing module, an analog to digital conversion circuit, a wireless communication module, an antenna and a power supply. The power supply is used for supplying power to the sensors, the ECU system, the signal processing module, the analog to digital conversion circuit, the wireless communication module and the antenna; the signals obtained by the sensors are processed by the signal processing module before being converted by the analog to digital conversion circuit, and then the signals are inputted into the ECU system; the ECU system is used for intelligently studying, analyzing and judging according to the information sensed by different sensors and the automobile key opening or locking signals obtained by the antenna; and when the environment in the automobile get worse or people / living things are left in the automobile and the automobile is locked, the ECU system is used for starting the wireless communication module to send short message to inform the occurrence of abnormal situation in the automobile. Adopting the technical scheme of the invention, the system has the intelligent fuzzy judging and adaptive learning capacity and does not need to obtain the automobile state information from the computer or other parts of the automobile.