With the wide application of temperature and humidity detection system, the requirements and standards of which in different industries and fields are various. After the analysis of domestic and foreign warehouse intelligent temperature and humidity control, the author has found a series of factors of that, and then puts forward a design of scheme of temperature and humidity detection system based on AT89S51, together with a plurality of digital temperature sensor DS18B20 and the humidity sensor HS1101, temperature and humidity detection system is formed.