**4. Conclusions**

(1) Aiming at the problems of low pickup rate and high wounded rate in potato sectional harvesting, a spring-finger potato picking device was designed, its working principle and key components were introduced, and the main design parameters of its components were determined by analysing key components such as spring-finger, drum disc, crank, roller and cam chute.

(2) The Box-Behnken response surface optimisation test method was used to analyse the effects of spring-finger speed, forward speed and embedded depth on the loss rate and wounded potato rate, to establish a regression model and to analyse their interaction, and the wounded potato rate was 4.98%. The results of the validation tests were basically consistent with the results of the optimisation analysis, indicating that the parameter optimisation regression model is reliable.

(3) Although the spring-finger potato picking device meets the design requirements of the picking process, there is still a certain wounded potato rate, and the subsequent research should improve the picking operation effect by optimising the profile of the cam slide.

**Author Contributions:** Conceptualization, L.W.; methodology, L.W. and F.L.; software J.Z. and J.L.; validation, L.W. and F.L.; investigation, X.Z. and J.L.; resources, L.W.; data curation, L.W. and Q.W.; writing—original draft, L.W. and X.F.; writing—review and editing, F.L. and S.X.; visualization, L.W. and F.L.; supervision, F.L.; funding acquisition, F.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the Science and Technology Program of Inner Mongolia Autonomous Region of China (2020GG0168), Inner Mongolia Autonomous Region Young Scientist Program of China (NJYT20B03), the National Natural Science Found of China (31901409) and the Science and Technology Research Project for Higher Education Institutions in Inner Mongolia Autonomous Region (NJZY21357).

**Institutional Review Board Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Conflicts of Interest:** The authors declare no conflict of interest.
