The work aims to explore the effect of the structural factors of honeycomb paperboard on its bending performance and rank the affecting degree of each structural factor on the bending performance of honeycomb paperboard, to optimize the structural design of honeycomb paperboard. The displacement-load curve of honeycomb paperboard was obtained by three-point bending test, and the bending strength and bending elastic modulus of honeycomb paperboard were calculated by combining the three-point bending test results with the structural parameters. The effects of face paper thickness, core layer thickness and thickness-to-span ratio on the bending performance of honeycomb paperboard were further analyzed by grey correlation entropy analysis. The ultimate bending load, bending strength and bending elastic modulus of honeycomb paperboard increased with the increase of face paper thickness and thickness-to-span ratio, and with the increase of core layer thickness, the ultimate bending load of honeycomb paperboard increased, but the bending strength and bending elastic modulus decreased. The thickness of the face paper has the greatest effect on the ultimate bending load of the honeycomb paperboard, and the thickness-to-span ratio has the greatest effect on the bending strength and bending elastic modulus.