The invention relates to an outdoor equipment monitoring system based on NB-IOT, and the system comprises an optical cable cross-connecting box monitoring unit, a mobile phone terminal unit and a network management platform management unit. The optical cable cross-connecting box monitoring unit comprises an access control terminal, an electronic lock and a Bluetooth key, and the access control terminal comprises an optical cable cross-connecting box state detection module, a battery, an electric quantity detection module, a lock driving module, an access control state detection module, an NB-IOT module and a Bluetooth module, which are connected with a central processing module. The central processing module communicates with the network management platform management unit and the mobile phone terminal unit through the NB-IOT communication module and the Bluetooth module, and the central processing module outputs a door opening signal and provides a power supply for the electronic lock. The electronic lock has corresponding lock cylinder information, and the Bluetooth key is used for receiving the unlocking authorization information of the network management platform management unit or the mobile phone terminal unit and is inserted into the electronic lock to supply power to the electronic lock. The system is low in power consumption, can further improve the management efficiency, and reduces the maintenance cost.