The rockfall impact disaster of engineering structures in mountainous areas is significant， and the energy dissipation buf? fer protection structure can effectively reduce the impact disaster. In view of the impact protection of piers， three energy dissipation structures are designed， including steel section?foam board， section steel?concrete and foam board?concrete. By analyzing the fail? ure mode and dynamic response process of three kinds of protective structures under rockfall， the energy dissipation mechanism of rigid flexible laminated protective structure is revealed. The test results show that the impact energy can be effectively diffused to the internal flexible buffer layer by using the rigid outer layer， so as to give full play to the energy dissipation of the rigid layer and buffering performance of the flexible layer； The concrete foam board protection structure has the best comprehensive performance. Compared with the non-protective structure， it can extend the impact duration of the rockfall impact reinforced concrete test board 9~10 times， and the average impact force is reduced to less than 1/10， which has good energy dissipation and cushioning perfor? mance.