Thanks to its unique properties piezoceramics has applications in various fields of engineering and technology. Disk piezoelectric devices are widely used in the elements of information systems. Mathematical model of piezoceramic disk transformer with ring electrode in primary electrical circuit is constructed. An estimate is obtained and calculated and experimental curves of the frequency dependence of the modulus of transformation coefficient of piezoceramic disk transformer with ring electrode in primary electrical circuit are compared in the work. As a result of research of real device’s mathematical model a set of geometrical, physical and mechanical and electrical parameters of a real object can be determined which provides realization of technical parameters of piezoelectric functional element specified in technical specifications. The cost of the saved resources is the commercial price of the mathematical model.