Viola inconspicua Blume was purified using the optimized alkali extraction and acid precipitation method. Leaf protein hydrolysates were prepared by enzymatic method. The components of leaf protein hydrolysates were separated by ultrafiltration, and their antioxidant activities were analyzed. The isolated hydrolysate components were desalted by solid phase extraction, evaluated by HPLC analysis, and assayed the inhibitory activities to tumor cells along with the effects on lifespan of nematodes. V. inconspicua leaf proteins could be stably extracted with the optimized parameters(ratio of material to liquid 1∶9, pH value of alkali extraction 10.0, and pH value of acid precipitation 4.5). The three selected proteases(papain, basic protease and flavor enzyme) could make most of hydrolysates with relative molecular weight less than 3.3×103, and ultrafiltration could isolate the groups of hydrolysate components with molecular weight of <1×103(PH1), 1×103-<3×103(PH2) and ≥3×103(PH3), respectively. The antioxidant activity and anticancer activity of the component PH1 were better than those of other components. PH1 and PH2 had similar effects on lifespan of nematodes, but both were superior to PH3. Therefore, the component PH1 of Viola inconspicua leaf protein hydrolysates had more application and development value.