Objective: This study aimed to investigate the factors influencing the oil yield of rapeseed during pressing in a double screw oil press. Methods: To simulate the pressing process of rapeseed and to explore the effects of two factors, the speed of the press screw and the porosity, on the oil yield. Results: The oil yield of rapeseed was linearly related to the porosity, and a larger porosity, was associated with a lower oil yield. Moreover, the oil yield was negatively related to the speed of the press screw. Conclusion: The oil yield of rapeseed was highest when the porosity was 0.45 with the speed of pressing screw at 20 r/min.