The invention discloses equipment for preparing Y type molecular sieve with low sodium and a high silica-alumina ratio and a preparation method. The equipment comprises a reactor (1), a first feed passage (2), a discharge passage (4), a second feed channel (3), a mixing device (8), reaction assemblies (7), a heating device (9), a gas-solid separation device (5) and a heat storage device (10), wherein the reactor (1) comprises at least one reaction assembly (7) distributed in the reactor (1) uniformly, and each reaction assembly (7) comprises at least one fluidized bed. When used for preparing the molecular sieve, the equipment has the advantages of short operation process, small sewage amount, low production cost, good reaction controllability, high reaction degree, low sodium content of a product, high silica-alumina ratio, adjustable silica-alumina ratio and uniform product property, causes no ammonia-nitrogen pollution and can perform large-scale continuous automatic operation.