Abstract: A three-dimensional model for small-radius planar curved tunnels with different bending angles is established to investigate their seismic response. The influences of bending angle, amplitude and type of ground motion are considered. The seismic response laws of the small-radius planar curved tunnels are obtained: (1) For the response amplitude, the transverse seismic section is the largest, the curve section is the second, and the longitudinal seismic section is the least. (2) For the response difference, the curve part has little effect on tunnel acceleration, which mainly affects the deformation of tunnel; (3) For the vibration energy, the energy decreases gradually with the transition from transverse seismic section to longitudinal one.