The existing theory on fatigue equivalent temperature of asphalt pavement does not take account of the nonuniform traffic volume distribution and the values of asphalt pavement temperature are unreasonable. To calculate the equivalent temperature in a more accurate and scientific way, the concepts of equivalent temperature and depth of asphalt layer were proposed and corresponding calculation methods were deduced. The relationship between the daily equivalent temperature of atmosphere and the equivalent temperature of asphalt layer was established. Taking the equivalent temperature at the equivalent depth of the asphalt layer as the representative temperature and dividing the temperature into different ranges, the dynamic modulus and fatigue tests on asphalt mixtures were carried out, and the frequency of traffic volume distribution in different temperature ranges was classified. Based on the Miner linear cumulative principle, a method was proposed for calculating fatigue equivalent temperature of asphalt pavement that takes the nonuniform distribution of traffic volume into consideration. The equivalent temperature values of two traffic volume distribution modes were calculated and comparative analysis was carried out. Results show that the equivalent temperature of asphalt layer could be used as representative temperature to divide temperature ranges. The proposed calculation method for the fatigue equivalent temperature of asphalt pavement could overcome the shortcomings of the existing methods theoretically by taking the nonuniform distribution of traffic volume into consideration, which makes the calculation of equivalent temperature more scientific and reliable. The calculated temperature of two traffic volume distributions had a difference of 1.6 °C. Compared with other methods, the proposed method had certain advantages. To further improve the accuracy of the calculation method, more intensified observation should be made in the future.