The invention discloses washable down feather composite fiber added with titanium dioxide and a producing method thereof, the washable down feather composite fiber is characterized by comprising the following raw materials by weight 13-15 parts of duck down, 17-19 parts of rabbit hair, 10-13 parts of alpaca hair, 15-18 parts of rabbit wool fiber, 12-14 parts of mercerizing australasian wool, 0.03-0.06 part of nano selenium, 0.1-0.3 part of poly (tetramethyleneether) glycol, 2-4 parts of nano attapulgite, 4-7 parts of perilla leaf, 1.1-2.4 parts of titanium dioxide, 1-3 parts of hedyotis diffusa, 0.4-0.7 part of hippocampus, 3-5 parts of fennel oil, 100-120 parts of 1 - butyl-3-methyl imidazole dimethyl phosphate, 110-130 parts of 1-butyl-3-methyl imidazole acetate, 2-4 parts of an additive and a moderate amount of water; by use of the technology of the present invention, the utilization rate of feathers can be can greatly improved, the washable down feather composite fiber has obvious social and economic benefits for resource development and utilization and sustainable development, at the same time, the washable down feather composite fiber is added with titanium dioxide and other components, washable, antibacterial, mouldproof, anti-oxidation, immunity-improving and other functions of the down feather can be improved.