Abstract: Safflowers can be one of the main characteristic economic crops in Xinjiang of western China. The medicinal components can also be found in the filaments of dry safflowers. The direct harvesting can fully comply with the national pharmacopoeia standards. Moreover, the uniform harvest time of dry safflowers is often required for the mechanical batch harvesting on a large scale. Therefore, there is an urgent need to develop an efficient picking machine for dry safflowers. There are some models for the dry safflowers picking at present, particularly with the high harvesting rate. However, it is still necessary to further optimize the efficiency of the picking. In this study, a slanted-roller brush picking device was designed for the dry safflower. The picking efficiency was also improved to optimize the various mechanical structures. The flexible brush threads were rotated to pick the dry safflower threads at the high speed along the height direction of the dry safflowers. The inclined-roller brushes were employed to extend the residence time of the dry safflowers in the picking area. Thereby, the picking rate was ultimately improved for the high picking efficiency. Firstly, the picking plan was determined, according to the planting mode, material characteristics and macroscopic parameters of the dry safflowers, including specific steps, such as feeding, picking and collecting the dry safflowers. Secondly, the structural parameters of the inclined-roller brush were determined as follows: The length of the roller brush was 1200 mm, the diameter of the roller brush was 70 mm, and the gap of the roller brush was 5 mm. The density of the hollow roller brush (PA-610) was 1.08~1.12 g/cm³, the tensile strength was 50~60 MPa, the flexural strength was 70 to 80 MPa, as well as the maximum and minimum diameters were 0.3 and 0.25 mm, respectively. Then, the theoretical analysis and simulation were conducted on the picking process. A systematic analysis was also made on the movement force and trajectories of the dry safflowers during picking. The results show that the low rotational speed, small pitch and inclination angle of the roller brush were necessary to obtain the high picking rate and low fruit injury rate. An interaction model between dry safflowers and roller brushes was established after optimization. The picking mechanism of dry safflowers was analyzed using the Hertz elastic contact theory. The influencing factors on the picking performance were determined as the rotational speed, inclination angle and forward speed of the roller brush. Finally, the single-factor experiments were carried out with the harvest rate and fruit injury rate of dry safflowers as the experimental indicators. The specific values of each factor were determined to be 500-700 r/min, 15~25°, and 0.2-0.4 m/s, respectively. The Box-Behnken experiment was also conducted to optimize these parameters. The results showed that: The optimal parameters were the rotational speed of the roller brush at 512.5 r/min, the inclination angle of the roller brush at 15°, and the forward speed at 0.30 m/s. The theoretical picking rate was 91.17%, the injury fruit rate was 0.27%, and the actual picking rate was 88.97% under these conditions. The fruit injury rate was 0.21%, while the relative errors were 2.2 and 0.06 pecental points, respectively. The findings can provide the technical references for the research and development of the dry safflower pickers.