This paper explored the gene expression programming(GEP)to model the back-calculation of asphalt pavement structure for surface layer modulus,base modulus and subgrade modulus,and obtained the function expression correspondingly.Then comparatively analyzed the deviation between theoretical modulus and back-calculation modulus.The motivation theory deflection data used in the analysis was developed from the finite element method under the falling weight deflectometer(FWD)load.Finally,the result showed that it had good precision using GEP algorithm to back-calculate the modulus of asphalt pavement structure layer.The method could not only effectively overcome the shortcomings of traditional method and lowly be effected by initial value,but also could obtain the aim function expression and be convenient for engineering application.