A thermoeconomic assessment and multi-objective optimization of a novel CCHP and multi-effect desalination (MED) hybrid system driven by an internal-reforming solid oxide fuel cell (IR-SOFC) and a micro gas turbine (MGT) are presented to comprehensively evaluate the hybrid system performance in this research. Firstly, the sensitivity analysis of system key design parameters such as steam to carbon ratio, compressor pressure ratio, pinch point temperature difference, motive steam pressure of MED and inlet pressure of ORC turbine on energy, exergy, economic, and thermoeconomic performance is investigated. It is indicated from the analysis results that the proposed hybrid system could produce power, cooling, heating and potable water which are 300.0 kW, 7.358 kW, 8.757 kW and 0.1715 kg/s, respectively. The system total cost and total cost per unit exergy are $9.838/h and $14.75/GJ under the design condition. A multi-objective optimization by using NSGA-II method is further implemented to obtain the ideal system design parameters and optimal system exergy efficiency, freshwater production, and total cost per unit exergy by setting four groups of different weights to these three objectives. The three-dimensional and two-dimensional Pareto frontier curves of the optimization results are depicted to reveal the relations between the objectives. It is validated that the system exergy efficiency and the system total cost per unit exergy are conflicted with the freshwater production.