In order to effectively prevent and control the rutting problem of asphalt pavement in the deep loess area of Eastern Gansu and reduce road diseases, diatomite was added into the asphalt mixture for laboratory tests. Through Marshall test and rutting test, the optimum mix proportion of the diatomite asphalt mixture, and the optimal mix amount of the diatomite in this area were determined. The pavement performance of activated diatomite asphalt pavement and SBS asphalt pavement in this area is compared and analyzed through laboratory tests and on-site road paving. The test results show that under the same ambient temperature, the activated diatomite asphalt pavement has the advantages of lower surface temperature, high stability, and low-water permeability coefficient than SBS modified asphalt pavement. In addition, by fitting the fatigue test data of these two asphalt pavements, it is found that the fatigue life of diatomite asphalt mixture is more sensitive to the change in stress level and has better fatigue resistance. Therefore, it is concluded that the use of diatomite modified asphalt pavement in the loess area can improve the temperature stability of the pavement, prolong the service life, and reduce the cost of construction, which can be popularized.