Abstract: Considering the load capacity of the shaking table, a light-weighted servo-controlled flexible air bag loading system was designed and fabricated, which was used in shaking table model tests for load cases both setting and not setting a loosen-zone. Numerical models were also built for the same load cases. The results from model tests and numerical simulation were compared, showing consistence and the effects from the loosen-zone. It is then testified that the flexible loading system could be applied to dynamic tests on shaking tables. Results shows that the vibration feature of buried tunnel under certain depth itself is not obvious; acceleration responses of the tunnel structure and the surrounding rock is enlarged by the existence of a loosen-zone; with the loosen-zone, the damage of the structure is more serious; however, the loosen-zone does not change the strain response law of the tunnel structure. The adverse effects of the loosen-zone on the ground motion response of the tunnel structure can be concluded: 1) the refraction and reflection of the seismic wave occur at the interface between the loosen-zone and the surrounding rock; 2) the loosen-zone is weaker than the intact surrounding rock, and the local deformation is more likely to occur during the earthquake.