OBJECTIVE： To preliminarily explore the feasibility of achieving the optimal granulation interval of TCM preparations. METHODS： Using molding technology of Zhongjiefeng granule as model， factorial design was adopted for test， using comprehensive score which was weighted with grain yield and particle formation rate as investigation index， Origin 8.0 software was used to draw relationship effect diagram about comprehensive score of mixture with different moisture contents （extract powder - soluble starch） and wetting agent concentration， solid-liquid ratio； coordinate extraction was conducted by Screen Reader in Origin 8.0 software， and the optimal granulation interval of Zhongjiefeng granule under specific conditions was obtained. In the granulation interval， different batches of extract powder were selected for laboratory scale and prescription amplification test， and verification test was conducted. RESULTS： When extract powder-soluble starch was equal to 1 ∶ 2， there was an optimal granulation interval for Zhongjiefeng granule， which meant when material moisture content ranged in [2.0％， 6.0％]， wetting agent concentration ranged in [50％， 80％]， and liquid-solid ratio ranged in [15.3 mL/g， 18.6 mL/g]， the prepared Zhongjiefeng granule met the requirements. Comprehensive score of verification test were higher than 85％， which proved the prepared granule was qualified. CONCLUSIONS： The established method for exploring optimal granulation interval for TCM extract under specific conditions has certain reference function to solve the problems in industrial production of TCM granulation， such as large difference between batches and poor reproducibility.