FOT3220 is a 3.5-inch color screen version of the high-precision optical power meter newly developed by our company. In addition to providing superior dynamic range and linearity technical indicators, it is also equipped with a rich menu function design, covering threshold alarm configuration, maximum and minimum power changes Value real-time monitoring, frequency signal detection and visual fault locator functions. When used with our light source, it also has the function of automatically identifying the wavelength of light emitted by the light source, which greatly facilitates the test link loss test, and can store and upload the data record of the instrument test at the same time. The instrument provides a standard communication interface protocol, which is convenient for users to embed the system or the needs of secondary design and development. It is an ideal tool for current optical fiber engineering maintenance and communication teaching and research.