The low-temperature barn is not a frame structure. At present, the grain depot adopts thermal insulation roof structure, which further reduces the heat entering the depot due to the influence of outdoor temperature and solar radiation, improves the thermal insulation effect, and the thermal insulation effect is better than that of direct paste type. A special building for storing grain. Bag-shaped grain storage cellar in Yangshao culture period is the embryonic form of granary. By the Zhou Dynasty, the Spring and Autumn Period and the Warring States Period, more formal grain depots had appeared. From the pottery warehouses and caves unearthed in the Eastern Han Dynasty, it can be seen that there are two kinds of granaries prevailing in the Han Dynasty: round warehouses and square warehouses, both of which are elevated, supported by wooden columns to prevent underground moisture and floods, and have windows to facilitate ventilation, reflecting the quite reasonable design idea of 1000 years ago. Including Jia Cang in Sui and Tang Dynasties and Jing Cang Ba in Ming Dynasty, with further improved facilities, it is a famous large-scale grain depot in history. The grain warehouse in ancient Egypt was a cylindrical building with a circular roof. Some of them have wooden benches to protect grain from ants and other pests. The bench is paved with salt, and the hole above the barn is where the grain is put into the warehouse. Although the form and structure of modern grain depots have changed greatly, they are basically developed on the basis of the above ancient types.