The work aims to establish a constitutive model of honeycomb paperboard with the three cubed Bezier curve. The fitting degree of the fitting curve and the experimental curve was compared by fitting the experimental curve with MATLAB. According to characteristics of the three cubed Bezier curve, point P0 and point P3 which were the first and end points of the characteristic polygon P0P1P2P3 were taken as the points in the experimental curve. The three cubed Bezier curve with good fitting degree would be obtained by means of the following principles. Firstly, if the three cubed Bezier curve controlled by the characteristic polygon P0P1P2P3 was below the experimental curve, point P1 and point P2 should be moved upward. Otherwise, it should be moved downward. Secondly, if the opening of the three cubed Bezier curve controlled by the characteristic polygon P0P1P2P3 was larger than that of the experimental curve, the distance between point P1 and point P2 should be reduced. Otherwise, it should be increased. Thirdly, if the experimental curve had a long part with a small change in slope, the edge of the characteristic polygon corresponding to it was very long. Otherwise, it was very short. The stress-strain curve sectional fitted with the three cubed Bezier curve has good fitting degree with the experimental curve. It was feasible to sectional represent the constitutive model of honeycomb paperboard with the three cubed Bezier curve equation.