Organic-inorganic hybrid perovskites have received great attention from researchers at home and abroad because of their excellent photoelectric properties. At the same time, due to the unique gas-sensitivity and thermal-sensitivity properties of these materials, a lot of research has been carried out on the application of perovskite in sensors, including temperature, humidity, NO, O3, O2, HCl, EtOH, NO2, Hg2+ response. However, due to the common problems of organic and inorganic perovskite materials-stability and toxicity, the application of sensors is still limited. Based on this, the research group developed a new lead-free double perovskite material Cs2AgBiBr6 not only has excellent moisture-sensitive characteristics, but also has good stability in the atmospheric environment. The humidity sensor has a fast response (1.78 s) and recovery speed (0.45 s). By analyzing the humidity response of the material at different temperatures, it was found that the physical adsorption effect of water molecules on the surface of lead-free double perovskite is the main moisture sensitive mechanism of the material.