Abstract: The temperature variance of cold storage for fruit, in particular the large fluctuations, seriously affected the fruit quality of medium and long-term storage. This paper reports a simple method for the detection of the temperature of cold storage and temperature drift of temperature control instrument. The result showed that the main reason for the large temperature fluctuations was the temperature drift of temperature control instrument itself. According to the detection result, through improving the cell circuit in temperature control instrument，the temperature drift was controlled effectively, thus the temperature error was reduced. The margin of temperature drift error reduced from 3.5℃ to 0.3℃, the cold storage temperature fluctuations decreased from 5.3℃ to 1.4℃.