Abstract: Based on the on-line analysis of gas products and the construction of photocatalytic reaction system, a batch on-line chromatographic analysis with multiple reaction channels has been realized and the photocatalyst activity evaluation system is established.Through the connection with the experimental device, the on-line gas chromatographic analysis can detect the catalytic reaction product qualitatively and quantitatively in real time, improve the analysis efficiency and provide efficient, convenient and systematic services for scientific research work.At the same time, the established photocatalyst activity evaluation system can lay an experimental foundation for the research of photochemical conversion and use of solar energy and environmental protection technology.The device system has expanded the use function of the instrument, and with improved application scope, which provides reference for the research and development of chemical synthesis catalyst evaluation system.