To address the inefficiency and high cost of manual potato pickup in segmented harvesting, a dual-disc potato pickup and harvesting device was designed. The device utilizes counter-rotating dual discs to gather and preliminarily lift the potato-soil mixture, and combines it with an elevator chain to achieve potato-soil separation and transportation. Based on Hertz's collision theory, the impact of disc rotational speed on potato damage was analyzed, establishing a maximum speed limit (<= 62.56 r/min). Through kinematic analysis, the disc inclination angle (12-24 degrees) and operational parameters were optimized. Through coupled EDEM-RecurDyn simulations and Box-Behnken experimental design, the optimal parameter combination was determined with the potato loss rate and potato damage rate as evaluation indices: disc rotational speed of 50 r/min, disc inclination angle of 16 degrees, and machine forward speed of 0.6 m/s. Field validation tests revealed that the potato loss rate and potato damage rate were 1.53% and 2.45%, respectively, meeting the requirements of the DB64/T 1795-2021 standard. The research findings demonstrate that this device can efficiently replace manual potato picking, providing a reliable solution for the mechanized harvesting of potatoes.