The invention provides a technology for preparing bamboo fiber by 1, 4-butanediol in a solvent method, which comprises the steps of preparing bamboo into bamboo filaments; soaking the bamboo filaments in the solvent and heating to remove lignin, hemicellulose and other impurities on the surface of the cellulose; preparing into coarse bamboo fibre; beating the coarse bamboo fibre, washing with water simultaneously, and then spin-drying through a centrifuge; bleaching and cleaning; conducting mellowing to the bamboo fiber; soft-impressing the bamboo fiber; stowing fermentation and curing, and finally obtaining the bamboo fiber with spinnability after opening and carding. The solvent adopted by the invention has high boiling point and stable chemical property and can be recycled; the whole technological process does not generate black liquor and seriously pollute the environment, and belongs to clean techniques; the obtained natural bamboo fiber has the remarkable advantages of moisture absorption, quick dry, coolness, comfort, antibacterium, deodorization and the like; and the method has low cost and good economic benefit and environmental protection benefit.