the present invention relates to the field of medical instruments . specifically , a biodegradable cross - linked polymer and a manufacturing method therefor are provided . the cross - linked polymer is obtained by bonding crosslinkable reactive groups to terminal groups of a biodegradable prepolymer having two or more arms and further subjecting the prepolymer to thermal polymerization and / or light irradiation . the cross - linked polymer has an elastic modulus of 10 - 4 , 500 mpa , and a degradation rate of 3 - 36 months . a biodegradable vascular stent and a preparation method therefor are also provided . the vascular stent is formed by laser cutting of polymeric tubing having a three - dimensional cross - linked network structure . the vascular stent has ample mechanical strength , a high elastic modulus at body temperature , and a regulatable degradation rate .