The invention relates to a preparation method of a hierarchical pore AFI structured aluminum phosphate molecular sieve. A macropore-mesopore-micropore composite hierarchical pore aluminum phosphate AFI molecular sieve carrier is prepared through adopting an ionothermal synthesis technology. The molecular sieve synthesis process is carried out under normal pressure or a low self-generated pressure, crystallization conditions are mild, and an ionic liquid can be recovered and repeatedly used, so the method has the advantages of low synthesis cost, no discharge of acids, alkalis or waste liquids in the synthesis process, and environmental protection. The hierarchical pore AFI structured aluminum phosphate molecular sieve prepared in the invention, including macropores, mesopores and micropores, has potential application values in the fields of catalysis, adsorption and separation.