The invention discloses a refining method for medicinal sucrose. The refining method comprises the following concrete steps: juicing of sucrose, pre-filtration, pre-concentration, decoloring with activated carbon, re-filtering, impurity removal via a semi-permeable membrane, purification and crystallization, centrifugation, drying, etc. The refining method has the advantages that an activated carbon process is employed for decoloring, so production cost is greatly reduced compared with an ion exchange decoloring process, the problem of residual sulfur in sucrose produced by using a sulfur fumigation process is avoided, and product quality is improved; a semi-permeable membrane process is employed for impurity removal, so impurities in sucrose can be effectively removed; and through subsequent purification and ultrasonic crystallization, the prepared medicinal sucrose reaches standards prescribed in Chinese Pharmacopeia and meets medicinal requirements, the particle size of the sucroseis controlled in a range of 30 to 100 nm, and the prepared medicinal sucrose has moisture resistance and hygroscopicity.