The invention discloses a fish tank full-intelligent filtering system, and relates to the technical field of fish tank filtration. According to key points of the technical scheme, the system comprisesa frame, an upper-layer fish tank and a lower-layer fish tank; the lower-layer fish tank is provided with a water outlet, which is connected with a drain-pipe; one end of the drain-pipe is connectedwith a first filter unit; the first filter unit comprises a prefilter, a rough-filtration water storage tank, a first water pump and a graded filter, which are connected successively through a pipeline; the graded filter is connected with a seawater proportioner; the rough-filtration water storage tank is also connected with a second filter unit; the second filter unit comprises a protein separator, a second water pump and a filter vat, which are connected successively through a pipeline; and a water outlet end of the filter vat is connected to the upper-layer fish tank through a pipeline. Through the first filter unit and the second filter unit, different filtration effects are generated; and through the seawater proportioner, the content of sea salt in water is supplemented, which is convenient for the survival of different fishes and has the effect of improving applicability.