Abstract: Safflower is one of the most important cash crops. However, the safflower filaments can often suffer damage and shedding to cause harvest losses during natural air-drying. Their mechanical properties are required for low loss during harvesting. Numerical simulation has previously been performed on the interaction between filaments and harvesting machinery. In this research, the structural and contact parameters of the dried safflower filaments were measured and calibrated to provide data support. A discrete element model was also established to optimize the components. The mechanical properties of the dried safflower filaments were determined by combining the physical and simulation tests. Five-point sampling of the dried safflower filaments was conducted using a roller-brush harvester. The filaments were categorized into the intact, petal-, stalk-, and dual-damaged filaments, according to the damage targets. Three-view images were captured by an electron microscope. A three-dimensional model of the filaments was then constructed after image collection. A discrete element filling model was established using an automatic filling method, according to the external morphology and particle distributions of the filaments. Smoothness levels were greatly varied in the three-dimensional coordinates. The average mass of a single filament was measured at 0.0008915 g using an electronic balance. A super-depth-of-field microscope was then employed to obtain the filament volume. The density of dried safflower filaments was then determined to be 88.923 kg/m³. The collision recovery coefficient between the filaments and stainless steel, as well as the friction coefficient between the filaments, were measured using the free-fall and the modified inclined plane. The filament plates and columns were employed to verify the static and rolling friction coefficients. Results showed that the collision recovery coefficient between the filaments and stainless steel ranged from 0.0462 to 0.187, the static friction coefficient was from 0.229 to 0.322, while the rolling friction coefficient was from 0.077 to 0.091. Furthermore, the impact recovery coefficient was from 0.0305 to 0.2282, while the static friction coefficient was from 0.301 to 0.743, and the rolling friction coefficient was from 0.085 to 0.122, due to the interacting filaments with each other. A comparison was then made of the physical tests and the simulation. In the free-fall test, the rebound heights were 5.306and 4.858 mm, as well as 5.086 and 4.686 mm, respectively, with the relative errors of 4.15% and 3.54%, respectively, indicating the reliable measurements of the crash recovery coefficient. In the modified inclined plane test, the inclination angles were measured as 17.8° and 31.4°, while the simulated values were 17.58° and 31.32°, with the relative errors of 1.24% and 0.25%, respectively. Horizontal rolling distances were measured as 138.9 and 35.669 mm, while the simulation was obtained as 134.2055 and 34.8397 mm, with the relative errors of 3.38% and 2.32%, respectively, indicating the reliable measurements of the friction coefficients. The angle of repose was determined to be 46.618° using MATLAB software. The influencing factors were screened after Plackett-Burman optimizations with the steepest slope and Box-Behnken experiments. Ultimately, a combination of the optimal parameters was calibrated: a coefficient of static friction between filaments of 0.347, a coefficient of rolling friction of 0.086, and a coefficient of restitution of 0.211. The stacking angle was simulated as 46.172°, with a relative error of only 0.96%. Coupled gas-solid simulations were then conducted on the roller-brush device for the dry saffron filament harvesting using the DEM-CFD method. Bench validation tests confirmed that the filament loss rate was 4.78% in the harvesting mechanism, with a relative error of 8.43%, compared with the field trials. Both values were below the 10% error threshold in a typical simulation. A discrete element model can also provide a theoretical basis for the material properties of the dried safflower filaments and the mechanical harvesting.