In order to study the rapid start⁃up of biofilters in seawater recirculating aquaculture systems, this study investigated the removal effects of seawater biological fluidized bed on pollutants under different hydraulic retention time (HRT) and temperature conditions, and explored the impact on initiation of seawater biological fluidized bed. The results show that: HRT=1 h experimental group can achieve material conversion and return to equilibrium more quickly, which is suitable for membrane loading; the high temperature conditions (28 ℃) are suitable for fluidized bed initiation, and the biofilm attachment growth can be observed more quickly.