The lack of freshwater in many countries pushes authorities to utilize desalination units. Solid Oxide Fuel Cells (SOFC) have shown promising results to provide the power to establish a multi-generation system using hydrogen as a renewable source. In this article, to better improve the efficiency of the suggested integrated system, the waste heat of the SOFC is recovered through the application of a Kalina power cycle and Humidification-dehumidification (HDH) desalination unit. Liquefied Natural Gas (LNG) cold stream also utilizes the waste heat of the Kalina cycle (KC) to provide cooling and power simultaneously. As all the considered cycles of Kalina, LNG cold stream, and SOFC can produce power and as this amount of electricity would be higher than the grid's demand, a further Reverse Osmosis (RO) desalination unit is utilized to increase the output amount of freshwater in the proposed system. The main focus of this study is to perform the thermodynamic analysis of this tri-generation system, which can generate power, cooling, and freshwater. Results indicate that the exergy and energy efficiencies of the current suggested system when the current density of the SOFC is 550 (A/), is around 55% and 60%, respectively.