A preparation method of drug-loaded micelles of an absorbable vascular stent coating for angiostenosis in an infant is provided, including the following steps: S1: dissolving a drug to be encapsulated in an appropriate amount of an emulsifying agent, adding a chitosan-poly(p-dioxohone) amphiphilic block copolymer (chitosan-b-PPDO copolymer), and thoroughly mixing to obtain a drug-copolymer solution; S2: adding the drug-copolymer solution obtained in S1 dropwise to an emulsifying agent aqueous solution prepared in advance, and continuously stirring to obtain a stable drug-loaded micellar solution; and S3: removing the emulsifying agent from the micellar solution obtained in S2 through vacuum evaporation, stirring a resulting concentrate, and centrifuging the concentrate to obtain a supernatant; and filtering the supernatant to obtain a filtrate, and subjecting the filtrate to dialysis to obtain the drug-loaded micelles.