Disclosed are an aerogel with a hierarchical pore structure formed using a pulsed laser technology, and a preparation method and use thereof. In the preparation method, a nano silicon-containing inorganic material as a freezing element, a biomass polymer as a cross-linking agent, and deionized water as a solvent are mixed and a resulting mixture is left to stand and gelatinized to obtain a hydrogel; the hydrogel is frozen to form ice crystals therein, and the ice crystals are removed by freeze-drying to obtain a micron-nano porous aerogel; the micron-nano porous aerogel is subjected to customized millimeter-scale punching using a pulsed laser to obtain an aerogel with a millimeter-micron-nano hierarchical pore structure.