The review is devoted to the analysis of works in the field of creating electrically insulating heat-conducting polyimide composite films based on powders of micro and nanoparticles with high dielectric and heat-conducting properties for use as effective thermal interface materials in various electronic devices in instrument making. Particular attention is paid to studies on the effect of the size of nano and microparticles of inorganic fillers on the heat-conducting, dielectric, and physicomechanical properties of nanocomposite polyimide materials. The analysis of the results of work on the study of the dependence of thermal conductivity on the ratio of micron and nanosized particles in mixtures and their amount in polyimides and on the conditions of their polymerization to confirm the possibility of increasing the values of thermal conductivity of promising polyimide materials from 0.12 W/m•K to 5-10 W/ m•K.