The lower degree of mechanical harvesting sweetpotato has restrained the development of sweetpotato industry in China. The mismatches between agricultural machinery and sweetpotato agronomy are one of the main factors that affect sweetpotato mechanical harvesting. In this study, we used five sweetpotato varieties with different shape and size to analyze their effects on the mechanical harvesting of sweetpotato. The results showed that the damage rate of‘Xuzishu 5’was the lowest. So, this variety was more suitable for mechanical harvesting in fields than the other varieties. At the same time, by investigating the shape, breakage rate and potato-exposing rate, we found that there is an extremely significant linear relationship between the sweetpotato shape and the breakage rate, i.e., the higher the flat rate, the bigger breakage rate. However, there was no obvious effect on the potato-exposing rate. Therefore, we should take tuberous root with lower flat rate as well as of better agronomic characters in the process of breeding new sweetpotato varieties.