The invention relates to a method for refining a sulfonyl isoquinoline derivative generally known as a Fasudil hydrochloride medicament for treating cerebral spasm caused by subarachnoid hemorrhage. The method of the invention comprises the steps of purification and refining and salification, wherein the step of purification comprises washing with water, concentrating, acidifying, extracting and crystallizing; and the step of salification and refining combines the Fasudil salification and subsequent refining of the prior art. The purification, refining and salification method of the inventionhas the advantages of simplifying operation flow, shortening production period, reducing production cost, improving product quality and bringing a great convenience to industrial production.