The invention discloses a technology for cleaning a sapphire wafer. According to the technology, before coating and silk screen, the sapphire wafer is cleaned. The sapphire wafer is cleaned in an ultrasonic cleaner. The technology comprises the following steps of firstly, oil contamination removing, secondly, spraying, thirdly, dirty removing, fourthly, spraying, fifthly, residue removing; sixthly, spraying, seventhly, ultrasonic cleaning, eighthly, slow pull dehydration, and ninthly, drying and static electricity removing treatment after drying. According to the technology, using of strong acid and strong corrosive detergents is reduced, through separated multiple-time cleaning, the cleaning effect of the surface of the sapphire wafer is ensured, and the hazard to equipment and an operator is greatly reduced.