Modified asphalt mixture

The invention relates to a modified asphalt mixture, in particular to the modified asphalt mixture which is suitable for high-grade highway surfaces and capable of improving the stability of the highway surfaces. The asphalt mixture is composed of 1-6 parts of asphalt concrete modifiers, 4-6 parts of asphalt and 85-95 parts of gravel mineral aggregate through mixing, wherein the asphalt concrete modifier is mainly made of a natural crystalloid hydration magnesium aluminum silicate mineral richly reserved in the northwest and can be obtained through a series of physical and chemical activation processes of the mineral, the asphalt is a pavement petroleum asphalt, the gravel mineral aggregate is a mixture formed by 40-60% of gravel with a particle size of 4.75-16mm, 10-35% of sand with a particle size of 0.075-4.75mm and 2-8% of a filler. The high-temperature stability, low-temperature stability and water stability of the high-grade highways paved by the modified asphalt mixture are greatly improved, the servic