The invention discloses a preparation method of a hierarchically porous Y-type molecular sieve. The method comprises the following steps: mixing a silicon source and an aluminium source at 5-60 DEG C,and standing and aging the mixture to prepare seed crystal glue; mixing the silicon source, the seed crystal glue and the aluminium source at 15-70 DEG C, and stirring the mixture to obtain sol; mixing the sol, a co-structure- directing agent and a template agent, stirring the mixture for 0.5-8 h, heating the obtained sol to 90-120 DEG C, crystallizing the sol for 6-72 h, and performing filtering, washing, drying and roasting to obtain the hierarchically porous Y-type molecular sieve. The co-structure directing agent and the template agent adopted in the preparation method are cheap, available and small in dosage and are easily separated from volume phase; the obtained hierarchically porous Y-type molecular sieve is high in relative crystallinity, mesoporous channels are regular, microporous channels and mesoporous channels intersect, and mesoporous diameter distribution is uniform.