In order to study the protection performance of the cladding on a bridge pier under explosion loading, a numerical model of reinforced concrete slab under explosion was established with ANSYS/LS-DYNA and its validity was verified.Using this numerical model, the response and failure modes of a hollow rectangular section pier with and without cladding under explosion loading were analyzed and compared.The propagation process of stress wave, the failure mode of pier and the displacement of the pier surface opposite to explosion were observed.Meanwhile, the influence of the thickness of the cladding, the density and thickness of the core layer on the protective effect to the pier under explosion were further discussed.The results show that the damage degree of the pier under explosion can be significantly reduced by the attached cladding.When the thickness of the cladding increased from 1 cm to 3 cm and the thickness of the core layer increased from 10 cm to 30 cm, the displacement of the pier surface opposite to explosion decreased obviously.Within certain limits, the protection effectiveness increased with core density.This study can facilitate the application of lightweight cladding on pier protection against explosion.