The invention discloses a method and device for processing garment patterns. The method comprises the steps of creating a basic pattern for a garment of a style according to basic body parameters; creating a specification table according to the pattern grading amount between the basic pattern and each standard pattern; storing pattern parameters of the basic pattern and the corresponding specification table into a pattern grading database; receiving a garment customization order input by a user, and obtaining garment style information and customer body information in the garment customization order; obtaining style marks corresponding to the garment according to the garment style information; obtaining the basic pattern of the garment of the style from the pattern grading database according to the style marks; adjusting the pattern parameters of the basic pattern according to the body information of the customer to obtain a corresponding fit pattern; and outputting the fit pattern obtained after adjustment. According to the technical scheme, the problems that garment pattern making can only be performed by means of the experience of a garment pattern maker in existing personalized customization and the garment pattern making efficiency is low are solved.