Suitable strip-tillage effectively enhances crop productivity and soil quality in Northeast China, yet conventional strip-tillage machines suffer from inadequate soil fragmentation. To address this issue, this study developed a bionic auxiliary soil-crushing device for the equipment. Specifically, we conducted a theoretical analysis of the soil-crushing blade to identify the key structural parameters affecting operational performance, along with their optimal value ranges. The blade tooth structure was designed following the claw-toe contour of the Oriental mole cricket (Gryllotalpa orientalis) for enhanced efficiency. A two-factor (working width and working depth), three-level central composite design (CCD) experiment was carried out using EDEM 2021 discrete element simulation software, taking the soil fragmentation rate and operational resistance as response variables. The results suggested that optimal performance was achieved at a working width of 40.66 mm and a working depth of 50 mm. Field experiments demonstrate that the soil fragmentation rate increased as the operational speed rose. The addition of the auxiliary device contributed to a soil fragmentation rate of 94.54%, bringing about an 11.54% improvement compared to the non-equipped machine. This outcome also validated the accuracy of the simulation experiments. This research provides technical and equipment support for the further development of conservation tillage practices.