Using the analytical option of the Origin Lab computer program, the analytical dependences of the liquidus temperature on the composition for the PbTe-Bi2Te3, PbTe-Sb2Te3, Bi2Te3-Sb2Te3 boundary systems of the PbTe-Bi2Te3-Sb2Te3 ternary system were determined. Based on these dependencies and thermal analysis data of the ternary system, the analytical model of the temperature-composite dependence of the crystallization surfaces of PbTe, Sb2Te3, Bi2Te3 compounds and PbBi2Te4, PbBi4Te7, PbBi6Te10 phases in the PbTe-Bi2Te3-Sb2Te3 system was determined. The resulting equations made it possible to visualize the phase diagram of the PbTe-Bi2Te3-Sb2Te3 system from the side of the PbTe-Bi2Te3 in 3D coordinates. The analytical model of the phase diagram of the PbTe-Bi2Te3-Sb2Te3 system allowed constructing a threedimensional image of equilibrium phases from different angles, to obtain two-dimensional projections and to tabulate the coordinates of the phase diagram.