The invention relates to a bone screw. The bone screw comprises a screw pole and a screw cap, the screw pole comprises a polish rod section and a screw rod section, a degradable material layer is compounded on the peripheral circumferential surface of the polish rod section, and the outer diameter of the degradable material layer is less than or equal to the large diameter of the screw rod section. The screw pole and screw cap are made of metal material; the degradable material layer is prepared from one or the polymer of polylactic acid, polyglycolic acid, poly trimethylene carbonate, polydioxanone and poly epsilon-caprolactone. Through operation, the bone screw is stable in fixing effect and avoided from sliding after the fracture part of a patient is fixed and before the degradable material layer is degraded; in the later degradation process of the degradable material layer and after the complete degradation of the degradable material layer, the bone moves slightly to stimulate the full healing of the bone, the achievement ratio of operation is improved, and the healing effect of the fracture part is better.