A new overlapping technique for honeycomb paperboard was presented, which could easily be mechanized and automated. The side energy absorption performance of the overlapped honeycomb paperboard was researched. Comparative experiments were carried out for the new technology processed honeycomb paperboard and traditional manual processed ones, with the experimental results analyzed by multiple curve fitting. The results showed that the new overlapping technique for honeycomb paperboard was feasible. Under concentrated load, the maximum capability of side energy absorption of the new honeycomb cardboard was greater than that of the traditional ones. With the existing traditional manual process, there was no obvious change in side energy absorption performance when the thickness of the honeycomb cardboard was less than 40 millimeter, while the side energy absorption performance of honeycomb cardboard made with the new overlapping technique was enhanced with the increase in thickness.