The proposed method for using a computer graphics system for changing the shape of models of geometric solids with the aid of deformation is characterized in that it is used for producing geometric solids which mate with one another as they were relative to one another and have mating surfaces, which require manufacture with precision accuracy (up to 10 micrometers), for example toothed screws (cylindrical, conical) of a screw compressor unit, gear trains, gears of a gear pump and similar mating pairs of geometric solids. The proposed method consists in that deformation of a model (3) of a semifinished product (3) of a first mating solid (1) is performed with the aid of a model (7) of a first tool (7), whose surface is automatically calculated using several mathematical laws, each of which is a polynomial in which at least one of the coefficients represents one of several characteristics defining the geometry of the shape of the surface of the second geometric solid (2). Deformation of a model (4) of a semifinished product (4) of a second mating solid (2) is performed with the aid of a model (10) of a second tool (10), which represents a deformed target model (8) of the first solid (1). Furthermore, said deformation is performed in accordance with a law for a movement imitating the movement of the geometric solids (1), (2) which mate with one another during use relative to one another. The proposed device is capable of implementing the proposed method.