The invention discloses large-aperture permeable asphalt. The large-aperture permeable asphalt comprises the following components in parts by weight: 81-86 parts of heavy duty asphalt, 1.0-10 parts of compatilizer, 0.8-3 parts of high-polymer modifier and 0.5-4.0 parts of inorganic acid. A softening point of the large-aperture permeable asphalt is larger than 80 DEG C, the ductility of 5 DEG C is larger than 30cm, the ductility of 15 DEG C is larger than 80cm, the needle penetration degree is larger than 40(0.1mm, 25 DEG C), the dynamic viscosity of 60 DEG C is larger than 20,000pa.s, the sticky toughness is not less than 20N.M, and the toughness is not less than 15N.M. According to the large-aperture permeable asphalt disclosed by the invention, the excellent binding power function of an aggregate to an aggregate in permeable asphalt mixture is ensured, and special requirements of pluvial regions on the large-aperture permeable asphalt are met. The invention further discloses a preparation method of the large-aperture permeable asphalt, wherein an oxidization modification process is utilized, suitable basic materials and technical conditions are selected, and the large-aperture permeable asphalt is prepared by adding the high-polymer modifier, the inorganic acid and the compatilizer to the heavy duty bitumen molten by heating, ventilating and growing, so that the process is simpler and easily controlled, and the cost is low.