A theoretical model is presented describing the growth of Hg1-xCdxTe crystal by the tellurium solvent method under steady growth conditions. The model uses the one-dimensional time-dependent equations of species diffusion with the moving free boundaries of the solution zone determined via consideration of the phase diagram. Numerical solutions are presented for the growth of Hg0.8Cd0.2Te (x=0.2) crystal by the finite difference method. The iufluence of the temperature profile of the solution zone, the velocity of the travelling heater, the length of the initial solution zone and the temperature of the growth interface on the crystal axial composition of HgCdTe is discussed in detail. The simulation results are in good agreement with the experiment.