The invention discloses a silk fibroin sulfonation modification method and technical screening of anticoagulant properties of sulfonated silk fibroin, belongs to the field of biological (medical) materials, and mainly relates to the following steps: natural silk is boiled in an alkaline (0.5% (wt%) Na2CO3 water solution) for degumming, and rinsed with distilled water, then silk fibroin fiber is dried at the temperature of 50 DEG C, then the dried silk fibroin is reacted with chlorosulfonic acid, a corresponding sulfonated modified silk fibroin solution is obtained by all steps of a sulfonation process optimized by an orthogonal method, then is neutralized into a neutral solution by use of a sodium hydroxide solution, then cooled to room temperature, transferred into a dialysis bag for dialysis for 72hr, concentrated by rotary evaporation, and frozen and dried to obtain sulfonated modified silk fibroin powder. By the optimized sulfonation process, the use amount of the chlorosulfonic acid can be reduced, the anticoagulant properties of the sulfonated silk fibroin can be improved, the repeatability is good, the product is pure, and the composition is stable.