Abstract: According to the existing situation that calibration method of temperature and humidity of environmental test box is complex and inconvenient,a portable and intelligent calibrator was developed,and composition and detection principle of the calibrator were introduced.The calibrator uses collection function of analog signals integrated by microprocessor ADuC834,which makes the hardware circuit simplest.Through calculation of ADuC834 internal software, temperature and humidity values can be directly read,and the data are transmitted to a computer so as to facilitate the work of calibration.The results of test for the calibrator showed that the temperature measurement error is less than ±0.1 ℃ and humidity measurement error is less than ±3%RH,which achieves actual needs and enhances working efficiency.