In order to study the influence of lateral distribution of wheel tracks on the stress and fatigue performance of steel bridge decks, based on the finite element theory, a finite element model of steel bridge decks for suspension bridges was established, the equivalent stress of steel bridge decks with different parameters under different wheel loads was obtained at detail, and the fatigue damage degree was calculated. A vehicle wheel track distribution model was established mathematically, the distribution probability of wheel tracks at different position in the lane was determined, and a method for calculating fatigue damage considering the lateral distribution of wheel tracks was proposed. The results show that the stress amplitude at the joint between the U-rib and the diaphragm is less affected by the lateral distribution of wheel tracks, which is about 1.5 m, and it is not necessary to consider the multi-vehicle effect. The thickness increasing of U-ribs and diaphragms can improve the stress performance. The damage at the U-rib web is relatively less, but the damage near the top plate and the connection between the web and the bottom plate is more serious. The fatigue damage after considering the vehicle wheel track distribution has been decreased by 74%, so considering the position of wheel tracks can improve the accuracy of fatigue damage assessment.