6LoWPAN (IPv6 over Low power Wireless Personal Area Network) is a technology to realize the IP connection of wireless sensor network based on IEEE802.15.4 standard. The network congestion and energy consumption problem exists around the single bounder router under the existing single DODAG (Destination Oriented Directed Acyclic Graph) protocol. An embedded 6LoWPAN multi-gateway protocol and system was designed. The embedded gateway node has dual-mode communication function, which can realize the physical connection between WSN (Wireless Sensor Network) and fixed IPv6 network. The dual-mode gateway implements uplink and downlink routes by establishing an IP tunnel between the 6LoWPAN root border router and it. By supplementing and optimizing the existing 6LoWPAN protocol standard, the dual-mode node has intra-network and inter-network routing capabilities, so as to achieve multi-gateway architecture and multi-path routing function. The optimized multi-point interworking topology and traffic sharing algorithm was used to realize the effective load balance between uplink and downlink links, and also to reduce the energy consumption of multi-hop routing of nodes. Experiments were carried out on multi-gateway platforms and single gateway systems. The results show that the proposed scheme can achieve 6LoWPAN multi-gateway Ethernet access, reduce network node transmission delay and packet loss rate, and improve the overall network throughput.