Abstract: Aiming at the issues of high working resistance of potato harvesters, short service life of digging shovels, and difficulty in ensuring digging quality under the conditions of sticky and heavy black soil in the Northeast China region, improvements had been made to the digging device of the dualrow lifting and transport chain-type potato harvester, and a detachable anti-clogging potato digging device had been designed. Theoretical analysis methods were applied to study the digging process of the key components of the potato harvester, to clarify the main factors affecting the working resistance of the digging shovel of the potato harvester. Combined with the agronomic requirements for potato harvesting under sticky and heavy black soil conditions, a multi-factor orthogonal simulation test was conducted with travel speed, shovel width, and shovel inclination angle as test factors, and the maximum working resistance of the digging shovel and the maximum soil compression force as test indicators. The optimal parameters for the digging shovel to ensure a good soil crushing effect without causing potato damage were designed. That was, at a travel speed of 1.11 m·s^-1, a shovel width of 150 mm,and a shovel inclination angle of 30°, the maximum working resistance of the digging shovel was 566 N,and the maximum soil compression force was 152 N. Field verification tests showed that all the indicators met the requirements and were better than those of the improved integral digging shovel potato harvester.