Abstract: Aiming at the problem of low screening rate（high soil content） of FUM, triaxial mean size and critical damage pressure of FUM and soil were measured, by means of FUM and soil aggregate Statistical analysis of triaxial dimensions and mechanical properties test. The results showed that the triaxial size of FUM and the soil aggregates on the screen was not significant, and the critical extrusion force value of FUM and the soil aggregates on the screen was significant. Based on this conclusion, the efficient separation scheme of FUM and soil aggregates by screening and kneading method was proposed. The efficient separation test device for FUM was constructed. The optimum range for calculating the kneading force of screening and kneading device was 20-40 N, and the value range of the kneading monomer thickness was 0.2-0.4 cm. The quadratic regression orthogonal rotation test scheme was designed, the results showed that the influence of the feeding amount, the square term of the feeding amount and the square term of the conveying screening speed on the screening rate was very significant, and the kneading force, the interaction between feeding amount and the speed of the conveyor screening had a significant impact on screening rate. Feeding amount and the square term of the speed of the conveyor screening had significant effects on damage. Kneading force, interaction between feeding amount and conveyor screen speed, interaction between feeding amount and kneading force, and the square term of feeding amount had significant effects on damage. By Design-Expert.V8.0.6 software, the optimal parameter combination was obtained: feeding amount of 0.68 kg/s, conveyor screen speed of 0.38 m/s, kneading force 36 N, screening rate of 80.5%, damage rate of 12.6%, respectively. Field tests showed that the average screening rate of the separator was 79.18%, and the average damage rate was 13.34%, which could meet the agronomic requirements of mechanized harvesting of FUM.