The invention is a porosity carbon material having long durable nano-antibacterial and catalyst effects and its preparation method. The method is: adding zinc oxide nano-particles and silver salt powder (e.g. silver nitrate and silver acetate and so on) into an aqueous solution and allowing the both to uniformly mix in the aqueous solution, keeping the aqueous solution at a first temperature. The aqueous solution is formed by uniformly mixing compounds such as water, an alkali liquid, ammonia water (or ammonia gas), water-soluble acrylic powder and an aqueous adhesive and so on, wherein the alkali liquid is to convert silver salts as silver hydroxide. Since silver hydroxide forms brown precipitation in the aqueous solution, it may not be uniformly dispersed in the aqueous solution, ammonia water (or ammonia gas) must be added into the aqueous solution to ionize the precipitation of silver hydroxide as silver ammonia complex ions. The water-soluble acrylic powder is a water-soluble dispersant , after dissolving in water it allows zinc oxide nano-particles and silver ammonia complex ions to uniformly and dispersively suspend in the aqueous solution. The effect of the water soluble adhesive is to coat over surfaces of the zinc oxide nano-particles and the silver ammonia complex ions after the zinc oxide nano-particles and silver ammonia complex ions are uniformly mixed in the aqueous solution placing the porosity carbon material into an oven for baking it to achieve a second temperature immersing the porosity carbon material into the aqueous solution and performing stirring for a predetermined period so that a permeation effect is generated because of the temperature difference between the porosity carbon material and the aqueous solution to allow the aqueous solution smoothly permeates into surfaces and pores densely distributed inside of the porosity carbon material, and to allow the zinc oxide nano-particles and silver ammonia complex ions to permeate into the pores
