Objective: To determine the precise quantitative relationship between screening efficiency and motion parameters for reciprocating vibrating screen, and to obtain the movement parameters with the optimal screening efficiency. Methods: Rocky was adopted to accurately simulate the movement behavior for wheat grain and wheat stem in the screening process, many factors orthogonal simulation test was used to investigate the effect of vibration frequency, amplitude, vibrating direction angle and screen surface inclination angle on screening efficiency. Results: The movement behaviors of wheat in the screening process was consistent with the theory analysis, which verified the correctness and feasibility of numerical simulation using Rocky. The vibration frequency, amplitude, vibrating direction angle and screen surface inclination angle have significant influence on the screening efficiency, and there is significant interaction between these motion parameters. The optimal motion parameter combination was the vibration frequency of 10 Hz, the amplitude of 2 mm, the vibration direction angle of 45° and the screen surface inclination angle of 0°. Conclusion: A regression model reflecting the quantitative relationship between motion parameters of and screening efficiency for reciprocating vibrating screen was established, and the optimal motion parameter combination of reciprocating vibrating screen was obtained.