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The damage rate of potato seedlings was high when traditional potato cultivators were used in the early stage of potato emergence. The reason was that the potato seedlings in the early stage of potato emergence were vulnerable to damage. The traditional potato cultivator had a large amount of ridging, so the damage rate of potato seedlings was high during potato tillage. In order to solve this problem, a kind of disc potato cultivator was designed, which can not only adapt to the intertillage of potato at the early stage of seedling emergence, but also it was suitable for middle and late potato tillage. The structure and working principle of the cultivator were described, and the monomer of the ridging disc was analyzed theoretically, and the factors affecting the effect of the tillage operation were obtained. The depth of cultivation, locomotive speed and angle were used as the experimental factors, the rate of weeding and seedling injury were used as the experimental index. The test was taken place on June 1, 2019 at the Acheng Experimental and Demonstration Base of Northeast Agricultural University, and the machine was driven by a tractor. The test results showed that when the tillage depth was 0.13m, the forward speed of the locomotive was 4.6km/h, and the adjustment angle was 52°, the rate of weeding and seedling injury were respectively 95.2% and 3.9%. The test determined the optimal structural parameters of the ridging disk and verified the correctness of the theoretical formula. The experiment was carried out according to the agronomic requirements. Compared with the traditional potato cultivator, the ridging amount of disc potato cultivator had a large regulating range, which improved the applicable period of the machine, and it can achieve better tillage operation effect. The problem of too much ridging amount in the early stage of potato seedling emergence was basically solved by the machine. Compared with the traditional potato cultivator, it was more suitable for potato tillage operation. The research result provided an important theoretical and technical reference for the improvement and optimization of the driventype disc potato cultivator. 