The invention discloses a synthesis method of high-purity I-type (+)-(S)-clopidogrel hydrogen sulfate, which comprises the following steps: 1) mixing an acetone solution of L(-)-camphorsulfonic acid and an acetone solution of (+)-(S)-clopidogrel crude product to carry out salification reaction for 6-10, filtering after the reaction finishes, and treating the filter cake to obtain (+)-(S)-clopidogrel L(-)-camphorsulfonate; 2) dissolving the product obtained in the step 1) in a mixture of dichloromethane or ethyl acetate and water, regulating the pH value to 7-8, stirring for 10-60 minutes, standing to stratify, and treating the organic layer to obtain a (+)-(S)-clopidogrel pure product; and 3) dissolving the product obtained in the step 2) in an organic solvent, adding a crystal seed, stirring, adding an organic solvent solution of sulfuric acid, heating to 50-60 DEG C, stirring for 1-3 hours, cooling to room temperature, filtering, and treating the filter cake to obtain the high-purity I-type (+)-(S)-clopidogrel hydrogen sulfate. The method has the advantages of simple technique, high product yield and high product purity, and is suitable for industrial production.