The invention discloses a debris flow protection mechanism. The protection mechanism comprises a protection slope, and further comprises mounting plates, wherein the plurality of mounting plates are fixedly connected to the diagonal plane of the protection slope through slots, a buffer plate is rotationally connected to the internal center position of each mounting plate through a pin, and the bottoms of one sides, close to the pins, of the buffer plates are elastically connected with the mounting plates through extrusion springs. According to the debris flow protection mechanism, when debrisflow impacts push plates, the push plates rotate around the pins, so that clamping plates can be pulled to be one side far away from the buffer plates; after losing limitation, due to the action of the extrusion springs, the buffer plates bounce upwards, so that the buffer plates are erected; when the buffer plates are erected, supporting plates rotate around torsion spring rotating shafts, so that the supporting plates are clamped into limiting grooves to support the buffer plates, and the buffer plates are kept stable; and the erected buffer plates block the debris flow, so that the buildingheight required by the protection slope is further reduced to save the cost.