Aiming at the problems of weak terrain adaptability, unstable rolling depth, and serious straw pushing of the existing straw-rolling discs in the desert area of Xinjiang, this study takes the physical characteristics of the straw-rolling process as the starting point and designs a cam structure synthesized by logarithmic spirals and cosine curves, which combines the variable-position pressure knives and the sand-fixing wheels to form a simplified model that is Pressing straw, has a constant rolling depth, and can be disassembled. Based on the three-dimensional modeling method, multi-body dynamics and discrete element method coupled simulation to establish the key components composed of the wheel mechanism, revealing the motion mechanism in the working and non-working state, the mechanical properties between straw and the wheel section to get the theoretical explanation and mathematical model, complete the parameter change between the key components and the logarithmic helix–cosine curve of the reasonable variable position. Using Recurdyn-Edem coupled simulation to analyze the effect of variable position sand fixing wheel in the process of straw into the sand, the results visualize the influence of the wheel part between the pressure knife, spring, and cam joint on the straw and sandy between the characteristics of the straw, 0.5 m/s when the straw erection is the best effect, when it reaches 0.7 m/s there will be a depth of unstable and with the phenomenon of grass, which means that the speed increases the sand blocking effect is poor; in the experimental process less than 0.5 m/s speed, the straw pressure operation efficiency is low resulting in the straw erection angle is not good, so it can be concluded that the structural design of the wheel part and the working speed affect the effect of the pressure of the straw. The design of the variable-position sand fixing wheel mechanism provides a new idea for inhibiting sand activity in the desert.