The flow form and the mixing machine of the particle materials in a gravity storage bin were presented through experiments . the calculation of the flow rate was proposed when the materials passed through the hole of the vertical pipe . the mixing index calculation model of estimating the particle mixing result was determined to be used in pilot tests for the characteristics af the gravity mixing . it proved the design reasonableness of the pilot test gravity mixing storage bin 通过实验介绍了颗粒物料在料仓中的流动形式及颗粒混合机理,提出了粒料通过垂直管开孔的流率计算方程,针对重力掺混的特性,确立了评价颗粒混合效果的混合指数计算模型,用于中试实验,证明了中试重力掺混仓设计的合理性。