Abstract: Traditional root-tuber crops digging shovel has many disadvantages, such as high resistance, poor soil leading, and badly concentrated nut effect, and so on. According to the disadvantages mentioned above, a multifunctional curved-surface shovel was designed. In order to improve digging penetration performance and oil separated rate, longitudinal plane of digging shovel was designed with two combined sections of ploughshare surface and arc surface. To make soil mattress smoothly and improve concentrated nut effect rate, transverse plane of digging shovel was designed with multifunctional combined sections of spline curve fitting. Comparison test with wide applied ordinary traditional planar polygon shovel shows that, with multifunctional curved-surface shovel, soil-separated rate is improved 4.8% and nut-gathering rate is improved 1.2%, nut-losing rate is reduced 1.03%. However, the digging resistance in their moving process is similar. The design of digging shovel provides reference resources for subsequent clamping device and soil separated device operation.