In order to study the factors that the influence of the cassava stalk toughness. Orthogonal experiments were used to test cassava stalk with MW-4 universal testing machine And the influencing factors were selected, for cassava stalk variety, placed time, and colliding parts. The results show that: effect of varieties on the impact energy is the largest, while, the impact energy was the smallest when the variety is SC6, placed for 12 days, and the the upper part collision site. Effect of varieties A on the impact toughness is the largest. The impact toughness is the smallest when the variety is SC6, the moisture content is placed for 0 days, and lower part collision position. The average impact energy and impact toughness of the lower part of cassava stalk are higher than the upper part.