Abstract: The excitation controller is an integral part of the gas turbine generator units. With the increase of the service time of the generator unit, the excitation controller becomes a component with high failure rate. In order to improve the automation level, test accuracy and test consistency of excitation controller maintenance and testing, and to enhance maintenance efficiency, a test system is designed. The LabVIEW software platform is used to develop a highly efficient, reliable, and stable test system for excitation controller of gas turbine generator units, which can greatly improve testing and maintenance efficiency. This article introduces the working principle of the excitation controller of gas turbine generator units, as well as the hardware and software design of the test system.