Abstract: This is an article in the field of ceramics and composites. In order to study the influence of diatomite content on the physical properties, rheological properties and road performance of asphalt mixtures, the basic physical tests, rheological tests, high temperature stability and low temperature crack resistance tests were carried out on asphalt mixtures under different diatomite content.The results show that when the diatomite content is 30%, the softening point, cone penetration and ductility of the asphalt mixture reach the maximum. When the diatomite content is 40%, the penetration of the asphalt mixture reaches the maximum. The law of change in ductility shows an increasing trend. The temperature is 170 ℃ as the preparation temperature of the asphalt mixture. The 30% diatomite content can be selected as the optimal value of low temperature crack resistance of asphalt mixture. At the same time, adding diatomite can effectively improve the high temperature performance of the asphalt mixture, but excessive incorporation of diatomaceous earth will weaken its high temperature performance. As the content of diatomite continues to increase, the variation of some characteristic peaks in the infrared spectrum of asphalt concrete shows a decreasing trend. During the aging process of asphalt concrete, its internal light components are affected by high temperature, and volatilization occurs. However, as the content of diatomite continues to increase, the characteristic peak-to-peak value of the light component of asphalt concrete after aging has not changed much.