Preparation of bismuth selenide nanoparticle

The invention discloses a method for preparing bismuth selenide nano particles, which comprises preparation of starch solution, preparation of bismuth nitrate solution, preparation of sodium selenide sulfite solution, preparation of bismuth selenide colloidal solution and preparation of the bismuth selenide nano particles so as to obtain a novel semiconductor quantum dot material of the bismuth selenide nano particles, wherein the used raw material is nontoxic bismuth nitrate, the used surfactant or stabilizing agent is nontoxic pollution-free soluble starch, the used solvent is nontoxic pollution-free purified water, the used precipitating agent is nontoxic pollution-free acetone, and the used washing agent is nontoxic pollution-free acetone or anhydrous ethyl alcohol, so the method has little harm to human body and pollution to environment, has simple and reasonable process and lower cost for preparing the bismuth selenide nano particles, and develops a new way for the non-oxide semiconductor quantum dot ma