Fine-denier cellulose fiber and preparation method thereof

The invention discloses a fine-denier cellulose fiber and a preparation method thereof. The fine-denier cellulose fiber mainly comprises cellulose, has fiber linear density of 0.56-0.89dtex and is provided with a lot of holes on the surface. The preparation method of the fine-denier cellulose fiber comprises cellulose solution preparation, spinning stock solution blending preparation, spinning molding and aftertreatment. In the spinning stock solution blending preparation, a functional polymer solution and a cellulose solution are mixed; through adjustment of a molding bath composition, the cellulose and the functional polymer are synchronously subjected to spinning molding to form cellulose fibers; and in the aftertreatment, the functional polymer is removed from the fibers so that fiber linear density is reduced and thus the fine-denier cellulose fiber is produced. The fine-denier cellulose fiber has a porous structure so that the fiber has good functionality.