The dehydration of waterlogged archaeological artifacts is an important step of heritage conservation areas,which is directly related to conversing quality of the cultural relics [1,2].When supercritical CO2 extraction drying technology is employed to dehydrate the relics,the dehydration process become safer and easier,with the natural properties of CO2 and the supercritical extraction process:the CO2 gas will not be liquefied since the temperature is above its critical point,and gas/liquid interface disappears in the absence of liquid phase relative to the surface tension of the drying process [3-5].Compared with the conventional dehydration techniques,supercdtical CO2 extraction drying technology has the short-drying processing cycle,high efficiency dehydration,small drying stress and so on; it also can sterilize and clean the cultural relics [6,7].In this paper,the dehydration drying process of the Warring States waterlogged bamboo lacquer (water content greater than 200%) was studied with the application of the supercritical CO2 extraction and drying technology.The optimal process conditions for supercfitical CO2 drying the waterlogged bamboo and lacquer,where drying temperature is 50 ℃,drying pressure is 25 MPa,CO2 flow rate is 20 Kg/h and dehydrated time is 5 h,are obtained from the orthogonal design test.Under optimal drying conditions,the water in the bamboo lacquer can be reduced to 15% or more lower,and its patent leather can be protected perfectly.Moreover,the dried bamboo lacquer is recovered in bright color,good shape,and no shrinkage cracking or other damage,which are consistent with the requirements of heritage preservation dehydration [8].