Multi-channel online monitoring system for VOCs

The invention relates to a multi-channel online monitoring system for VOCs. The multi-channel online monitoring system for the VOCs comprises a flue gas sampling probe, a pretreatment system, a hydrogen absorption pre-verification system and a hydrogen flame ion detector; the flue gas sampling probe is arranged in a flue gas channel and is used for sampling flue gas; the flue gas sampling probe isconnected with the sample gas inlet of the pretreatment system; the sample gas outlet of the pretreatment system is connected with the inlet of the hydrogen absorption pre-verification system; and the outlet of the hydrogen absorption pre-verification system is connected with the sample inlet of the hydrogen flame ion detector; the hydrogen absorption pre-calibration system comprises a flowmeter,a hydrogen absorption unit and a residual hydrogen calibration unit, wherein the hydrogen absorption unit is connected with a hydrogen source through a pipeline. According to the system of the invention, ethylene is subjected