In order to improve distillate water, this paper presents a study of the solar dome system that is considered as one of the most important economical solutions in the domain of drinking water production. For this, a mathematical model was built from equations describing the optical and thermal phenomenon involved in this process. The concentration of radiation and the heat flow were simulated in each 0.1m² of the dome which using the metrological parameters of Morocco’s region Rabat-Salé-Kenitra. The results can follow the evolution of the temperature of glass, salt water, point dew temperature, saturation pressure and evaporation rate as well as humidity reached in August month for the study zone. For this, a numerical implementation on Matlab and Ansys are compared with measurements for the same parameters showed in the domain study of single slope. The comparison results are more significant by the rise of the ray concentration rate reached until 99% if the inclination angle of the heliostat divided into three intervals. The saturation pressure increases as long as with the rate of evaporation and the humidity that produces ordinary daily fresh water.