Metasurface are micro-nano optical devices composed of sub-wavelength unit structures capable of modifying the phase, amplitude, and polarization of light waves through structural design, thereby enabling light field control. Optical sensors detect minute objects by leveraging light-matter interactions based on principles such as absorption, emission, and fluorescence. Metaoptical sensors, which harness the physical and design flexibility of metasurfaces, exhibit superior performance. This paper presents the technical background of metaoptical sensors, elucidates their operating principles, and discusses their diverse application scenarios. It concludes with an outlook on the future development trends of metaoptical sensors.