The invention provides a hierarchical porous molecular sieve and an alkali treatment solid-phase synthetic method thereof. The synthetic method comprises the following steps: 1) subjecting a solid-phase silicon source, an aluminum source, a template agent, an alkali source and a seed crystal to grinding, carrying out mixing, then carrying out a crystallization reaction, and subjecting a product obtained by the crystallization reaction to filtering, washing and drying over a fire so as to obtain a solid-phase synthesized molecular sieve; and 2) treating the solid-phase synthesized molecular sieve by using an alkali solution under a hydrothermal condition so as to obtain the hierarchical porous molecular sieve. The hierarchical porous molecular sieve and the alkali treatment solid-phase synthetic method thereof provided by the invention have the following advantages: the technical process is simplified; the yield of the molecular sieve is improved; water and solvents are not needed to be used in the process of solid-phase synthesis; the discharge of waste liquid is reduced; the cost is saved; the pollution is reduced; potential economic values and social values are obtained; and the obtained multi-stage pore molecular sieve has the advantages of hierarchical porous channel recombination, good crystallinity and small particle size.