Abstract: A simples, variable temperature heating unit has been successfully developed,which be quickly and easily installed on the X-ray diffractometer,without any replacement of D8 X-ray diffractometer attachment cases. In situ variable temperature X-ray diffraction test,meeting the demand from room temperature to 600℃ in-situ temperature X-ray diffraction test can be carried out, shortening the time of replacement of the attachment from 2~3 days to 30 min. The test efficiency is improve. A fund of nearly 20 million has been saved from the purchase of a similar variable temperature heating device.