For difficulties and deficiencies for complex geologic body and structural engineering with FLAC3D, the three-dimensional complicated model was built by using MIDAS/GTS-FLAC3D coupling technique, which was based on the Kangjiagou-bridge-Miaoliang-tunnel project crossing the mined-out regions in Liulin section of Qingdao-Yinchuan highway. The interactions between the mined-out regions and surface structures such as the tunnel lining and bridge were analyzed as the following sequence of operations: the mining process step-by-step was performed corresponding to the years, and then the grouting treatment was carried out after mining coal in Kangjiagou, next, Miaoliang tunnel was excavated and Kangjiagou bridge was constructed. The surface deformations under different working conditions were revealed, and the ground subsidence basin characteristics were analyzed. Also, the deformations and forces of key bearing parts of the tunnel lining and bridge structure were predicted in order to guide the engineering design and construction. The above-mentioned results have important theoretical meaning for guiding the similar engineering practice.