Abstract: A hierarchical porous polymeric material and its preparation method in the field of porous polymeric materials provided. The preparation method comprises: (1) mixing hydrophobic silica particles, an initiator, a polymerizable monomer, a crosslinking agent, a co-crosslinking agent and a pore-forming agent together, uniformly stirring to obtain a reaction mixture; (2) adding water into the reaction mixture and stirring until a gel emulsion is formed; and (3) carrying out staged thermal polymerization on the gel emulsion to obtain the hierarchical porous polymeric material. The present application can effectively regulate and control the contents and sizes of pores and throats, and obtain a material with hierarchical micro-porous structures. The good heat transfer and zero explosion in the polymerization process enable high product qualification rate. The wet material has rich pores, small resistance in mass transfer process and fast drying rate.