The invention discloses a method for manufacturing three-dimensional bone tissue engineering bracket through extruding deposited 3D printing, and belongs to the technical field of biological materials. The method comprises the steps that gelatin, sodium alga acid and water are uniformly mixed according to a certain ratio; then nano-sized hydroxyapatite is added; hydroxyapatite-gelatin-sodium-alga-acid composite slurry is formed after uniform mixing; the qualification ratio of water to gelatin to sodium alga acid to hydroxyapatite is 100:(4-6):(2-4):(30-55); the composite slurry is charged intoa 3D printer to print a tissue engineering bracket; and the printed tissue engineering bracket is subjected to primary freezing and drying treatment, curing treatment, cleaning and secondary freezingand drying treatment, so that the final bone tissue engineering bracket is obtained. The bone tissue engineering bracket manufactured on the basis of 3D printing technology has miniature pores and good biological activity, good degradability and strength, and has extremely high application value in the field of bone damage repair.