Ground-heaped load often leads to complex stresses on existing shield tunnels, which can cause deleterious effects, such as cracking and uneven deformation. The mechanical behavior of shield tunnels caused by ground-heaped load was analyzed to examine the influence of ground load on the force and deformation of shield tunnels and reduce and prevent harm to shield tunnels caused by ground load. The mechanism of ground-heaped load that affect shield tunnels was also explored. The internal forces of lining were calculated with and without ground-heaped load and the results of forces were compared using the modified routine method of lining design theory. Finally, the deformation laws of tunnel were examined based on different magnitudes and locations of ground-heaped load by employing 3D software MIDAS/GTS NS. Results show that ground load can lead to the settlement of the tunnel, wherein the maximum settlement increases linearly with increasing ground load. The settlement of tunnels decreases as the distance between the stacking center and the tunnel center increases, whereas horizontal displacement increases before decreasing. The bending moment, axial force, and shear force increased by 69.34%, 51.90%, and 67.11%, respectively, compared with those measured without ground-heaped load. The conclusions obtained in this study have an important guiding significance for predicting and controlling the force and deformation of shield tunnel caused by ground-heaped load in practical engineering.