The impact of key physical properties on granulated products by the high-speed mixing wet method was studied. Andrographis extracts were utilized as the model drug. Four processing methods were adopted to prepare mixed powder of microcrystalline cellulose (MCC) and starch with the mass ratio 1:0.5, 1:1 and 1:2 by the high-speed mixing wet method. The properties of the prepared granules were evaluated with such indexes as granule yield, the ratio of lumps and fine powder, granule-AOR and granule-HR. The impact of key physical properties on granulated products was analyzed through stepwise regression analysis. The results showed that angle of repose, moisture content, pore volume, density and contact angle with water were key physical properties of the powder. The key physical properties of Chinese medical extracts powder are the important factor impacting granulated products made by the high-speed mixing wet method. In this study, the impact of key physical properties on granulated products of Chinese medical extracts was analyzed from the physical angle.