Abstract: As an effective source of power,compressed air and its drying technology has an important role on reliable applications and energy saving in various fields.This paper systematically introduced the development overview of compressed air dryer domestic and aboard,as well as the principles and devices of refrigeration and adsorption dryers.In addition,it made a brief analysis of the direction and development prospects of separator device,and pointed out the using of waste heat,reducing energy consumption and improving the efficiency would be the main direction of future research and development.