The present work summarizes parametric optimization technique of multi effect desalination with thermal vapor compression (MED-TVC) process to increase gain output ratio (GOR) value. In order to increase GOR value, a simulation model of MED-TVC system is presented. This simulation can provide engineers a cost-effective tool for thermodynamic design, development and optimization of the thermal desalination plants. Also, a mathematical model has been developed which can predict the effect of all parameters on total capacity, performance ratio of the system, temperature difference between effects and pressure on each effect under design and operating conditions. The transient nature of temperature during the seasons is modeled by ordinary differential equations based on mass and energy balance. An actual system is used to compare GOR values of theoretical and experimental results. In this paper, it is shown that by means of parametric study, the computer simulation tool developed will help designers to achieve the best setting for desalination process to increase GOR value and minimize the energy consumption. The comparison between the simulation results, with experimental data well proves the validity of parametric study.