The invention belongs to the technical field of atmospheric environment detection and spectral measurement and particularly relates to a portable multi-component gas infrared spectrum detection system. The system comprises a portable case, an infrared source, an infrared interferometer, a sample cell, a gas pump, an infrared detector, a data acquisition card, a computer and a power supply module, and the infrared source, the infrared interferometer, the sample cell, the gas pump, the infrared detector, the data acquisition card, the computer and the power supply module are mounted in the portable case. The portable multi-component gas infrared spectrum detection system which is capable of realizing online real-time detection of multi-component gas concentration can be applied to various fields of atmospheric environment detection, such as fields of emergency monitoring of emergency atmosphere accident sites, pollution source emission monitoring, atmospheric environmental monitoring of chemical industrial parks, gas detection in a catalytic conversion process and the like, and reliable equipment is provided for atmospheric environmental monitoring.