The invention discloses a high-efficiency volatile organic matter online monitoring system. The high-efficiency volatile organic matter online monitoring system comprises a sampling probe system, a back flushing system, a preprocessing system, an online chromatographic instrument, a PLC control system, a hydrogen generator, an air generator, a high-purity nitrogen generator, a data processing system and a data acquisition instrument, wherein the online chromatographic instrument is in communication connection with the data processing system, the data processing system is respectively in communication connection with the data acquisition instrument and the PLC control system, and the PLC control system is respectively in communication connection with the sampling probe system, the back flushing system, the preprocessing system, the hydrogen generator, the air generator, the high-purity nitrogen generator and the DCS. By adopting the high-efficiency volatile organic matter online monitoring system, not only can a content of volatile organic matters contained in waste gas be accurately measured, but also dust attached inside a probe and at the outer side of a filter can be effectively removed in a blowing manner; and moreover, condensed water can be avoided, the measurement accuracy can be effectively improved, and meanwhile the entire processing period is relatively short.