The invention discloses a hexagonal honeycomb, a preparation method and application thereof. The hexagonal honeycomb includes a plurality of hexagonal honeycomb units and plastic films arranged on the upper surfaces and lower surfaces of the honeycomb units, each honeycomb unit has six side walls, two sides walls in the vertical direction between the honeycomb units are not connected, and the remaining four side walls are the common side walls of two neighboring units. According to the hexagonal honeycomb, the plastic films are fused on the upper surface and the lower surface of the hexagon, the upper surface and the lower surface of the hexagon are all sealed, thus overcoming the problem of line contact between a round tube honeycomb surface layer (various sheets) and a honeycomb core layer, realizing surface contact and greatly improving the strength. Two side walls in the vertical direction between the honeycomb units are not connected, certain gap can exist, thus endowing a honeycomb plate with better sound and heat insulation benefits. The method provided by the invention can realize automatic continuous production, and compared with traditional honeycomb production lines, the production efficiency can be increased by 8-10 times. The honeycomb does not contain any glue or other harmful solvents, and can realize 100% recovery.