A new technique of complex modelling of seismic, gravity and thermal data is developed basing on forward gravity modelling and thermal conjugacy problem for layered media with piecewise thermal conductivity values. The method is based on the approximation of the inverse thermal conductivity coefficient with combination of step functions. It allows one to do the practical interpretation of heat flux observed values using density model and statistical data on the relation between thermal physical parameters distribution in Earth’s crust and upper mantle with density distribution. Using the constructed models, a crustal and mantle components of heat flux are selected. Then these component and their recalculations may be matched with structural zoning maps.