77.38%。Many factors have effects on the separating ratio, moisture contents of the stems and leaves in fresh chopped alfalfa drying and separating processing. Four major factors: inlet temperature, inlet velocity, rotational speed of rotary drum, and feeding speed were analyzed in leaf-stem separation equipment. A quadratic orthogonal rotation design with 4 factors was introduced to do the regression analysis. Then models were developed and optimized. The results showed that the developed models fit the experiment data well. The inlet temperature affected the drying and separating processing most significantly and then the let velocity, rotational speed of rotary drum, feeding speed, respectively. It was analyzed that the most optimized parameters were 400℃ of inlet temperature, 14m/s of inlet velocity, 12r/min of rotational speed of rotary drum, and 8kg/min of feeding speed, respectively. Under these conditions, the leaf moisture content was 13.42%, the steam moisture content was 14.24%, and leaf-steam separation ratio was 77.38%.