Tea is a kind of global beverage, the mechanized tea refining operation is an important part of the entire tea mechanization process. Vibrating-sifting is an integral part of tea refining, which directly affects the purity of tea. In view of the unclear mechanism of vibrating-sifting in the process of tea vibrating-sifting, there are problems such as broken tea and hanging mesh, which affect the vibrating-sifting efficiency. The motion law of tea on the screen bed was researched, the dynamic model of the three-stage screening process of tea moving up and down along the screen bed was established, which was thrown up from the screen surface and colliding after falling to the screen hole, combined the motion law of tea on the screen bed, a simulation model of tea screen bed was established through EDEM, and the speed and force of tea on the screen bed were analyzed. The best parameters were crank radius, rotating speed of the crank and the inclined angle of the screen surface. Finally, through the orthogonal test of three factors and three levels, the software Design-Expert was used to analyze and optimize the experimental data and determine the optimal parameters. The significance order of each factor on the error screening rate and productivity was obtained. The order of significance for the error-sifting rate was the inclination angle of sifting bed, crank speed and crank radius, while the significant order of the productivity was the inclination angle of sifting bed, crank speed and crank radius. When the crank speed was 247.99r/min, the inclination angle of the sieve bed was 2.60°, the crank radius was 23.11mm, the error screening rate and productivity were 5.3% and 440kg/(m2·h), respectively, compared with the optimization result, the error was within the allowable range. The research result had a significant reference value for improving the screening efficiency of vibrating-shifting machine for tea.