The paper describes a digital system for designing matrixes of self-regulating heating cables, consisting of the following subsystems: prediction of the electrically conductive properties of the matrix, prediction of the deformation-strength properties of the matrix, mathematical modeling of the relationship "composition-technology-properties", multifactorial modeling of the structure, 3D modeling of the composite semiconductor matrix, formation Database. The functionality of each subsystem is considered and their necessity is substantiated in the design of polymer composite materials with a positive thermal coefficient of electrical resistance. The possibility of both creating new semiconductor composite materials and selecting known compositions to meet specified technical requirements is substantiated.