Modeling is carried out for the low-voltage distribution network intelligent gateway test system. The main content of the distribution automation gateway test is analyzed. The intelligent gateway system architecture is proposed, the software and hardware system of the interconnection test access platform is analyzed, and the test process is proposed for the interconnection and interoperability test of the intelligent gateway of the substation. The interconnection communication scheme based on Ethernet and wireless communication network is analyzed. According to the 104 protocol interconnection test plan, the test process and test method of a single smart gateway, multiple smart gateways, and smart gateway modularity are analyzed. The simulation cases of substation telemetry, remote control, and remote signaling are analyzed to illustrate the effectiveness of the test system in this paper.