Abstract: In order to research on the effects of uprooted speed and distribution status of cassava storage root in soil on the uprooted force on cassava storage root，mechanical and mathematical model of uprooted force on cassava storage root considering the effect of uprooted speed were established by using the physical test method, explicit dynamic simulation software ANSYS/LS-DYNA and soil mechanics theory to have physics experiment and mechanical analysis, and then the models were verified. The results showed that the mechanical model of assumption uprooted force on cassava storage root as interaction of a disc and its extension on the soil was reasonable; mathematical model of maximum uprooted force on disc was highly precision, and the most fractional error between theoretical value and measured value was less than 16%; mathematical model of maximum uprooted force on cassava storage root has higher precision in uprooted force of cassava storage root, which distribution and growth both were like disc-shaped；mathematical model of uprooted force on cassava storage root has lower precision in uprooted force of cassava storage root, which distribution and growth both were uneven，but the most fractional error between the theoretical value and measured value also was less than27%；with the increasing of uprooted speed, the diameter and depth of root disc, the maximum uprooted force on cassava storage root increased. The most influence factor on the maximum uprooted force on cassava storage root is depth of root disc, followed by diameter, and finally uprooted speed. The design foundation is provided for uprooted mechanism system of storage root in dig-uproot cassava harvester.