The invention provides a multi-component gas detection device. A sampler pumps a mobile phase containing a sample gas and a carrier gas into a micro chromatographic column module. The micro chromatographic column module adsorbs the gas components in the sample gas to separate the gas components. A micro infrared gas detection module analyzes the components in the gas sample and expresses the components in the gas sample through a weak electronic signal. A data processing module amplifies, collects and processes the weak electronic signal and outputs an analogue signal. An upper computer module converts the analogue signal into practical concentrations of the gas components in a well and displays the practical concentrations. The multi-component gas detection device integrates micro chromatographic separation technology, micro infrared gas detection technology and data collection and processing and the like, thereby achieving ground real-time on-line detection of multi-component gas. The device overcomes the defects in a conventional on-ground multi-component gas on-line detection technology and is high in detection speed, is high in detection precision and is wide in application range.