A message transmission method and related devices are provided in the disclosure. The method includes the following. A first long range (LoRa) device creates a LoRa mesh group. Based on a peer-to-peer (P2P) communication requirement with a second LoRa device belonging to the LoRa mesh group, the first LoRa device switches to a P2P communication mode, transmits a mode switching instruction to the second LoRa device, and increases a transmission priority associated with a target message type to a predetermined transmission priority. The mode switching instruction is used to instruct the second LoRa device to switch to the P2P communication mode. The target message type is the type of a message that needs to be transmitted in P2P communication between the first LoRa device and the second LoRa device. The first LoRa device transmits a message of the target message type to the second LoRa device.