A method for generating an aligner configured to be coupled to a tooth, the aligner having a body defining a channel arranged for receiving the tooth and a fixing block arranged for coupling the aligner and the tooth, the method comprising acquiring a tooth model, defining a zone on the tooth model, determining, based on the zone, a tooth-coupling surface for coupling the tooth with the aligner, generating, based on the tooth model, a body model by generating an inner surface of the body model based on the tooth model, generating, based on the determined tooth-coupling surface, a fixing block-coupling surface indicative of an outer surface of the fixing block by extruding the tooth-coupling surface by an interference length to inward of the tooth model so as to generate a block model having the fixing block-coupling surface, generating the aligner model by joining the block model with the body model.
