Hexagonal honeycomb were manufactured using plant fiber paper as raw material, and the mechanical properties, fire retardant and water absorption of plant fiber honeycomb were tested. The result shows that the compression property and L direction shear properties of the plant fiber honeycomb are lower than those of aramid paper honeycomb, which could fulfill the requirements of Q/6S 1015-2005; The average char length of plant fiber honeycomb is 35mm, the max smoke density in 240s is 16.2; the water absorption rates of 1.83-48 plant fiber honeycomb is 5.5%, and the retention rate of compression strength of honeycomb is 87.6%; the phenolic resin dipped into the interior of the plant paper, thus the honeycomb holes become thinner than aramid paper honeycomb, and the gum area becomes smaller, correspondingly.