The invention relates to a private network dual-mode communication system. The system comprises a service master station, a wireless private network, a PON network and a dual-mode terminal. The service master station communicates with the dual-mode terminal through a wireless private network. The service master station communicates with the dual-mode terminal through a PON network. The dual-mode terminal comprises an ONU module, a wireless private network module, an HUB module and a power supply module, wherein the power supply module supplies power to the ONU module, the wireless private network module and the HUB module, the HUB module is connected with downlink equipment, the HUB module is also respectively connected with the ONU module and the wireless private network module, the ONU module is connected with a PON network, and the wireless private network module is connected with a wireless private network. The system has the advantages that the system is provided with multiple interfaces and can communicate with other devices in multiple modes, and the service requirements of a power grid are met; the PON network and the wireless private network form a double-channel full-protection switching type topological structure, and the stability of system communication is guaranteed.