The drop cushioning performance at the edge of EPE was experimentally studied to verify the limitation of the current calculation method for edge drop equivalent area, and to explore a calculation method for dynamic equivalent area. By conducting dynamic impact tests, the effects of three different contacting forms including edge contacting, V type contacting, and edge contact with corrugated paperboard container on the equivalent area were compared, and the relationship of the side-length and edge-length in the edge cushioning structure with the cushioning effect was studied. Acceleration level-static stress curves obtained by dynamic impact experiments with three different contacting forms showed that increasing side-length in the edge cushioning structure lowered both the acceleration and static loading under the condition of constant equivalent area, whereas the change of side-length had little contribution to the cushioning effect in actual application. The existing theory cannot be regarded as a reliable method in edge drop calculation in cushioning design. Change of edge length possesses more cushioning function compared to side length in edge drop state of a packaging.