Abstract: There are still problems of high soil content and wounded potato rate in the existing transport and separation devices of potato harvesters in China.A S type lifting chain conveying and separating device was designed and analyzed.By comparing and studying with the first-class and the second-class transport chains，the damage of potatoes and the effect of soil removal could be reduced and improved，respectively.Results showed that by controlling linear speed，inclination angle and turning drop of the S type chain conveying and separating device，casualty rate and impurity content could reach 0.06% and 1.74% respectively，which also indicated that comprehensive operation of the machine was good and met technical specifications for quality evaluation of potato harvester and actual production requirements.