In order to meet the need of partition harvest and picking of peanut, a kind of half feeding type peanut picker was designed through the investigation on the present situation of peanut production mechanization and picking methods in China. The structure and working principle of the half feeding type peanut picker were briefly introduced. The power of the transmission system adopts a diesel engine. The transmission system has two branches, which is respectively clamping and conveying transmission system and picking transmission system. The picking device adopts the differential phase matching structure of the two blade type picking roller, and the roller is inclined configuration installation. The clamping and conveying device adopts the clamping structure of the single clamping chain coordinated with conveyor guide. Through the performance test of the picker, the influences of the roller rotate speed and clamping and conveying speed to peanut picking rate and picking breakage rate are tested. The test results showed that the influence of the picking roller rotate speed was extremely significant to peanut picking rate and picking breakage rate; the influence of the clamping and conveying speed is significant to peanut picking rate, but is not significant to peanut picking breakage rate; on the condition of the working requirements, all performance indexes of the peanut picking machine can satisfactorily meet the operation quality requirements of the half-feed peanut picker. The research played a significantly practical guiding role in the design of the new type half-feed peanut picker, and can provide technical foundation for designing peanut harvesting machinery in the future.