Abstract:Technological conditions of preparation of pueraria micro-powders were optimized by orthogonal array design tests.Pueraria micro-powders were produced by vacuum drying with ultra-fine pulverization methods while taking fresh pueraria as raw material.The results showed that the optimal condition of vacuum drying was material thickness 2 mm，drying temperature 75℃，vacuum degree 0.08 MPa.And the optimized technology was as follow as over 80-meshs sieve，moisture of 4.00%preliminary powder，feeding quantity was 80.00 g and time was 3 min for ultra-fine pulverization.The average diameter of particle of micro-powder was 8.2 μm and the yield reached 70.87%under the above optimal condition.The rate of enzymatic hydrolysis，dilatations，solubility，viscosity，electrical conductivity of micro-powders（d≤26 μm）were obviously improve than those of whole powders（d＞94 μm），but its precipitability was strong.