The invention discloses a cellulose acetate blended hollow fiber forward-osmosis membrane based on metal organic frame MIL-53 (Fe) and a preparation method and belongs to the field of membrane separation. 16.0%-35.0% (w/w) of cellulose acetate, 5.0%-20.0% (w/w) of polyethylene glycol or polyvinylpyrrolidone, 0.05%-2.0% (w/w) of surfactant, 0.1%-2.0% (w/w) of MIL-53 (Fe) and 41.0%-78.85% (w/w) of mixed solvent formed by N-methyl pyrrolidone and acetone are added into a dissolving tank according to a certain sequence, and the mixture is mixed and dissolved at the temperature of 25 DEG C to 90 DEG C for 5-16 hours and subjected to standing and defoaming to obtain a blended hollow fiber forward-osmosis membrane casting membrane fluid based on the MIL-53 (Fe); the hollow fiber forward-osmosis membrane is obtained with a dry-wet method and subjected to thermal treatment in deionized water with temperature of 30 DEG C to 90 DEG C for 10-60 mins, then the cellulose acetate blended hollow fiberforward-osmosis membrane based on the MIL-53 (Fe) can be obtained. According to the prepared forward-osmosis membrane, 1M NaCl is used as a driving liquid, the deionized water is taken as a raw material liquid, in 1h of testing time, the pure water flux can reach 28.5 L/m<2> h or above, and the reverse salt flux is smaller than 1.5 g/m<2> h.