Abstract: In recent years, IOT technology has continued to advance and breakthrough, and the global IOT industry has seen explosive growth. Bluetooth Low Energy Mesh has emerged as a highly competitive communication method compared to other mesh protocols. However, existing BLE Mesh only considers managed flooding protocols for data transmission. When the size of the network or the amount of transmitted data increases, the network will be filled with a large amount of redundant data, resulting in increased energy use. To address the energy consumption problem, this paper proposes a node-combined on-demand routing protocol for BLE Mesh. Firstly, the node-combined network topology is established through three steps: neighbor node information exchange, node combination configuration and node combination full connectivity. Secondly, route probe packets and route reply packets are used to obtain the shortest path of all transmission paths. Finally, the source node sends packets sequentially along the shortest path. The protocol reduces the number of forwarding nodes by limiting ordinary node forwarding and allowing only leader and relay nodes to forward packets in order to suppress redundant packets. Simulation on MATLAB R2022a compares this node-combined on-demand routing protocol with a managed flooding protocol. The results show that the protocol reduces the total number of packets in the network by 92.43% when the source node transmits 100 packets, thus reducing the energy consumption. Moreover, the more packets the source node transmits, the better the result.