In order to solve the problem of low efficiency and potential damage in the separation of Gentiana roots from soil, a reciprocating adjustable striking-vibration combined device was designed, along with its performance testing. The ranges of working parameters for the vibration mechanism, striking mechanism, and adjustable reciprocating mechanism were determined through dynamic analysis of the mechanisms and materials. The effects of vibration frequency (X1), crank speed (X2), and screw feed speed (X3) on the threshing efficiency (Y1) and damage percentage (Y2) were studied using a ternary quadratic regression orthogonal combination experimental method, combined with response surface analysis to explore the interaction effects of these factors on the indicators. A regression model was established through variance analysis. The significant factors affecting Y1 were X2, X3, and X1 in that order, while the significant factors affecting Y2 were X1, X3, and X2. In the interaction of factors, X1X2 significantly affected both Y1 and Y2; X1X3 had extremely significant impact on both Y1 and Y2; and X2X3 had extremely significant impact on Y1. The optimal working parameters for the root-soil separation device of Gentian were determined to be vibration frequency of 6 Hz, crank speed of 204 r/min, and screw feed speed of 15 mm/s. With this combination of parameters, experimental tests yielded a threshing efficiency of 90.8% and a damage percentage of 5.9%. The relative errors compared with the theoretical optimization results were less than 5%. This study meets requirements for the root-soil separation of Gentiana.