A novel honeycomb structure, a honeycomb plate having the honeycomb structure and a foamed plate having the honeycomb structure are provided. The honeycomb structure comprises first octagon plates, second octagon plates, first connecting plates, second connecting plates, third connecting plates and fourth connecting plates. Four first side edges of each first octagon plate are connected to third side edges of four second octagon plates through the first connecting plates. Four third side plates of each second octagon plate are connected to the first side edges of the four first octagon plates through the first connecting plates. Four second side edges of each first octagon plate are connected to fifth side edges of the fourth connecting plates through the second connecting plates. Four fourth side edges of each second octagon plate are connected to sixth side edges of the fourth connecting plates through the third connecting plates. According to the honeycomb structure, when the force direction of the first octagon plates or second octagon plates is not parallel to the vertical direction, the honeycomb structure still has high supporting force, the honeycomb structure is not liable to destroy, and an application range is wide.