In the field of low temperature，cryostat is the most commonly used experimental device to measure the performance of samples at low temperature．Samples often need to carry out basic experiments on electrical，optical，magnetic and thermal properties under the condition of low temperature and constant temperature．It analyzes and explores the concept，composition，classification and structure of cryostat，describes the progress of cryostat，and puts forward the development trend of cryostat in the future．