The invention relates to a preparation method for regenerated fibroin fiber, which comprises the following steps: taking regenerated fibroin water solution containing calcium ions as spinning liquid, extruding the spinning liquid out from a spinning nozzle in the temperature range of 5-35 DEG C, then curing the spinning liquid into silk in air directly, taking alcohol-water mixed solution as a finishing agent for post-processing, then taking the silk for drying, and finally obtaining the regenerated fibroin fiber. In the invention, the raw material source is wide, the cost of the raw material is low, and in the whole process, the defects that the traditional wet spinning solvent and the coagulating bath are strong in corrosion, and are toxic; in addition, compared with the other regenerated fibroin fiber dry spinning fiber, the condition of the spinning liquid is optimized, the PH regulation and other complex steps are omitted, and the use of a series of solvent is avoided. Therefore in the method, the cost is saved, and simultaneously the environment is protected. The regenerated fibroin fiber has the advantages of being non-toxic, harmless on human body and the like, is good in biocompatibility, suitable for biological and medical materials, and has good application prospect.