Fuente: Wipo "IOT" The application of the invention is a divisional application of a Chinese application with the application number of 202010759007.7. The invention provides an NB-IoT (Narrow Band Internet of Things) network system based on a local area wireless ad hoc network and a networking method. The networking method comprises the following steps: forming a local area ad hoc network among a plurality of NB-IoT devices to realize communication between any two NB-IoT devices; the comprehensive weighted value of each NB-IoT device is calculated, the NB-IoT device with the highest comprehensive weighted value in the local ad hoc network is taken as the NB-IoT device node of the communication, and the comprehensive weighted value comprises the comprehensive weighted value of the signal strength weighted value and the battery electric quantity weighted value of the NB-IoT device; and the NB-IoT device needing communication in the local area ad hoc network is connected and communicated with the external NB-IoT base station through the NB-IoT device node. According to the invention, the problems that the NB-IoT equipment cannot receive the NB-IoT network signal and the NB-IoT network signal cannot be transmitted at high power due to insufficient battery can be effectively solved.