Abstract: The aim of this study is to solidify the volatile oil (VO) of Bupleuri radix and forsythiae fructus by using mesoporous silica Sylysia 350FCP (Sylysia 350FCP) as carrier, and to investigate the changes of micromeritic properties before and after drug loading. The volatile oil drug-loading powder (VO-DLP) was prepared by blending process. The micromeritic properties were evaluated by angle of repose, particle size, bulk density, true density and porosity. The compressibility and compactibility of the powder were evaluated by plastic strain energy, ejection force, friction energy and tensile strength. The powder was characterized by scanning electron microscopy, powder X-ray diffraction and synchronous thermal analysis. In addition, the thermal stability, mechanical stability and other key properties of VO-DLP were investigated. We found that mesoporous silica as a carrier of solidifying volatile oil has the advantages for large drug load, high thermal stability, and high mechanical stability. In addition, the excellent properties of mesoporous silica as solid lubricant and glidant are not affected after loading VO, and has no effect on the compression process and compactibility of materials. What's more, it can meet the demand of continuous production.