The sweep method widely used in a thermal conduction problems, is applied for calculation of the multistream counter-flow heat exchanger in which are some direct and some inverse streams. In this case the problem of boundary conditions is mathematical and thermodynamic solved. Nonlinear correlations of coefficients are solved by organization of iterative procedure. The method is applied to the heat exchanger with 11 streams. Results of tempe-rature field calculations give a great volume of information for an analysis of the solutions accepted at projection. It is shown as not optimum distribution of streams in 2…3 times worsens thermal performances of the heat exchanger. Merits and demerits of application of a sweep method surveyed. Problems of the method application for the heat exchangers with two-phase streams are emphasized. Comparison to alternative methods is carried out.