Due to the advantages of prefabricated structure, its applications in utility tunnels are increasing. However, more connection joints have raised concerns about the vulnerability of prefabricated utility tunnels in earthquake disasters. The main objectives of this research are to analyze the seismic response, vulnerable parts and failure modes of a prefabricated utility tunnel. A pair of twin models of prefabricated utility tunnels with two‐compartment layouts were designed, and then set up to load ground motions synchronously through a large‐scale shaking table of 6 m × 6 m under two different boundary conditions: one buried inside a soil box and its twin laid outside the soil as a comparison. The results show that: the damage of the split‐type prefabricated utility tunnel is mainly concentrated in the connection joints, and the connection joint at the top corner of the compartment with larger cross section is the vulnerable part that needs special attention; the SSI effect has a great influence on the seismic response of the prefabricated utility tunnel, and the model buried inside the soil box shows stronger seismic response than its twin laid outside the soil. The experimental results and analysis in this paper can provide a helpful reference for risk assessment and prevention, seismic design, and structural optimization of prefabricated utility tunnels.