The invention discloses an online circulating detection intelligent control system for exhaust gas components during an industrial process. The system comprises a controller, a host computer, a gas circulating device, a gas path back-flushing device, a temperature control device, a gas component analysis device, and gas sampling heads arranged at N sampling points. Each gas sampling head is connected with one end of a sampling pipeline; and the other end of the sampling pipeline is connected with the gas circulating device. The outlet of the gas circulating device is connected with the gas component analysis device. The controller is used for completing sampling mode selection, sampling pipe/sample point switching control, sampling pipeline back-flush control, measurement data acquisition,and measurement data information output. According to the invention, circulating sampling or simultaneous sampling of a plurality of sampling measuring points on a large-sized gas circulation cross section is realized. Gas components of the plurality of sampling points are detected circularly based on various modes; the sampling point switching is realized automatically; back flushing of the sampling pipeline and the probe is carried out intermittently; and the gas component concentration distribution cloud chart on the cross section is generated automatically.