In order to reduce the loss of peanut caused by peanut plants stacking and throwing during two-stage peanut harvester working, a spring-finger cylinder pickup was designed by analyzing spring-finger swing and movement rule of a sliding spring-finger cylinder pickup in four processes of picking, lifting, pulling, and null swing with peanut harvest agronomic and plant physical and mechanical characteristics parameters, including spring-finger, crank, slide, shield, etc. which were optimized and designed optimally by NSGA-II for minimum shield radius. Equations of cam slide centerline locus were designed by using spring-finger swing characteristic. Cam slide centerline locus was obtained and smoothed by using Matlab and cubic non-uniform B-spline. The end displacement locus of the spring-finger was obtained by using ADAMS. The quintic polynomial was used in null swing station with spring-finger swing simulation analysis. The experiments of prototype working and collecting peanut plants indicate that, the phenomenon of peanut plants stacking and throwing was disappeared; the optimal working parameters of springfinger cylinder pickup were obtained by using response surface method: the forward speed was 48.0m/min, cylinder rotating speed was 53.1r/min, and height above around was -7.4mm. The collecting rate and the loss rate were 98.9% and 2.5% respectively under peanut plant moisture content of 15%~17% in two-stage harvest.