Abstract: In recent years, planar optode technique based on the principle of fluorescence sensing has been widely used in the fields of marine environment, lakes, plant roots, and water-sediment interfaces due to its advantages of high spatial resolution and in-situ real-time monitoring. In this paper, the basic principle, system components, and imaging measurement methods of planar optode imaging are introduced, the parameter characteristics of planar optode imaging are analyzed and the imaging characteristics summarized. This work aims to provide references for the system construction of planar optode and selection of measurement methods, and provide insights for the research and application of planar optode technique in fields like marine environment and geochemistry.