Abstract: The main structure and working principle of the twin-shaft horizontal total mixed ration mixer were discussed in the paper. For optimization parameters in structure and motion, the experimental method for the five-factor quadratics rotary orthogonal combination was adopted, and two evaluation indexes(mixing homogeneity and material powder) were applied in the experiment. By the experiment, the reasonable parameters in structure and motion were obtained, that is, rotational speed 40～50 r/min for rubbing rotor, 55～65 r/min for cutting rotor, clearance 11～13 mm, rod angle 5°～10°, mixing duration less than 10 min, loading coefficient more than 0.1. In the experiment, the coefficients of variation were analyzed by determination of salt content, experimental results testify that this method is accurate, simple, practical.