The invention discloses a humidity monitoring system and belongs to the monitoring system field. The humidity monitoring system of the invention comprises a plurality of humidity sensor units which are in signal connection, an MCU1 controller, a plurality of transmitters, a master receiver, an MCU2 controller and a monitoring PC host. The humidity monitoring system of the invention can simultaneously acquire humidity change data so as to monitor the humidity change of a large environment. The identification process of the humidity monitoring system is reliable. With the humidity monitoring system adopted, phenomena that one or more labels cannot be matched and recognized can be avoided, and monitoring accuracy can be ensured.