Abstract: Three types of superfine Pueraria thomsonii whole powder (designated SGP-1, SGP-2, and SGP-3) were prepared using a dry impact superfine grinder and compared with the Pueraria thomsonii whole powder prepared by a hammer cyclone mill (designated P-120) and the refined kudzu starch obtained by water extraction (designated KS). The effects of superfine grinding on the physicochemical properties, sensory quality, functional components, and antioxidant activity of the whole powder were systematically investigated. Results showed that SGP-2 and SGP-3 achieved particle size Dx (90) values of 19.60 μm and 19.16 μm, respectively, both meeting the criteria for superfine powders (<20 μm). Compared with KS, SGP-3 exhibited increases of 317.66 mg/kg in total flavonoid content, 0.12 g/g in water-holding capacity, 0.11 g/g in oil-holding capacity, 0.97 mL/g in swelling power, 44.26% in DPPH free radical scavenging activity, and 0.74 in total reducing power. Relative to P-120, SGP-3 showed increases of 17.5 points in overall sensory score, 3.17 in whiteness, and 21.68% in pasting transparency. However, the final viscosity of SGP-3 decreased by 288 mPa·s and 2097.33 mPa·s compared to P-120 and KS, respectively. Analyses such as scanning electron microscopy (SEM) indicate that the enhanced quality of the superfine powder was largely attributable to its finer and more uniform particle size. However, the intensification of starch damage and the destruction of crystalline structure during the ultrafine grinding process can also lead to a decrease in its final viscosity. In conclusion, Pueraria thomsonii whole powder exhibits superior functional properties compared to kudzu starch, and superfine grinding can effectively improve its edible quality.