Orthotropic steel decks (OSDs) show advantages such as light-weight, high performance and rapid construction. However, the OSD demonstrates notable fatigue cracking under the direct impact of vehicles, because of its massive welding works and complicated configurations. The deck-to-rib weld and the rib-to-beam weld are the two most outstanding and typical structural details. Considering the load correction by the traffic volume adequately, this paper analyzes the two typical details of OSDs with detailed finite element, in order to determine the fatigue stress range and perform fatigue checking. Different calculation methods are proposed according to the different structural details, through analyzing and comparing detail types of fatigue evaluation approaches. The results recommends the LSE method for the deck-rib weld and vertical rib-beam weld, and Dong method for the transverse rib-beam weld. The research output can offer references for the evaluation, design and application of OSDs.