The invention discloses a debris flow gabion prevention and control structural body and a design method of the debris flow gabion prevention and control structural body. The flexible debris flow blocking structural body aims to overcome the defects that an existing permeable dam is limited in water permeability and is cracked and destroyed easily by over large instantaneous impact force. The debris flow gabion prevention and control structural body comprises at least one gabion dam prevention and control structural single body. Each single body comprises a lower steel pipe pile group and an upper gabion dam, wherein the steel pipe pile group is formed by arranging a plurality of steel pipe piles in the transverse direction of a debris flow channel, the lower pile bodies of the steel pipe piles are embedded into a debris flow gulley bed, and the upper portions of the steep pipe piles are exposed out of the gulley surface and are connected with the gabion dam in a penetrating mode. The multiple gabion dam prevention and control structural single bodies are arranged adjacently in the longitudinal direction of the debris flow channel. Through the optimization design, the gabion dam is of a multi-layer structure, each layer of the gabion dam is composed of a plurality of gabion nets, and the gabion nets of each layer are arranged in a staggered mode. The invention further provides the design method of the debris flow gabion prevention and control structural body. The debris flow gabion prevention and control structural body can fully utilize the water permeability of the gabion combined structure and deformation feedback of the gabion combined structure on the impact to achieve a good prevention and control effect.