Because of its degradable and excellent cushioning properties, corrugated paperboard is commonly used in transport packaging. The strain-stress curve of corrugated paperboard with B-flute was obtained by quasi-static compression experiment. The constitutive relation was fitted using least square method. Then, according to the fitting curve, the cushion coefficient-max stress curve of corrugated paperboard with B-flute was calculated. At last, an example of the paperboard bearing calculation was given.