Artificial breeding method of grouper fry based on double-circulation system

The invention belongs to the technical field of artificial breeding of a grouper fry and particularly discloses an artificial breeding method of a grouper fry based on a double-circulation system. The method comprises the following steps: (1) in a preparation stage of breeding a fry, preparing a plurality of water tanks for breeding a fry and installing a set of a circulation system A and a set of a circulation system B, wherein the circulation system A and circulation system B are connected with a plurality of the water tanks for breeding a fry, and the system A and the system B operate respectively; (2) putting roes into the water tanks for breeding a fry in step (1), adding rotifers into the water tanks for breeding a fry after the roes are hatched out to produce fries, and starting the system A until the fries are 18 days old; and (3) starting to feed with a large plankton bait when the fries are 19 days old, closing the system A at the moment, starting the system B to remove residual bait, excrement and