This study presents an integrated techno economic evaluation and exergy analysis of a natural gas liquefaction process based on the propane pre cooled mixed refrigerant (C3MR) cycle. In this configuration, the propane cycle provides precooling, while the mixed refrigerant cycle supplies the main refrigeration for the liquefaction process. The process was simulated using Aspen HYSYS, and the system performance was evaluated in terms of thermodynamic efficiency, exergy destruction distribution among components, and economic indicators. A sensitivity analysis was also carried out to investigate the effects of key operating parameters, including natural gas flow rate and pressure, as well as mixed refrigerant and propane flow rates. The results indicate that heat exchangers have the highest share of exergy destruction at 47.63%, followed by compressors and expansion valves with 19.14% and 19.07%, respectively. In addition, the mixed refrigerant cycle and the propane precooling cycle contribute 69.54% and 30.46% of the total exergy destruction, respectively. From an economic perspective, heat exchangers account for more than 50% of the total equipment capital cost. The total capital investment was estimated at approximately 789.55 million USD, while the LNG production cost was 307.85 USD per ton. The annual net profit was calculated to be about 524.40 million USD, with a payback period of 1.5 years and a return on investment of 66.42%. Sensitivity analysis shows that increasing the natural gas flow rate from 350 to 450 t/h reduces the specific energy consumption from 1031 to about 801 kJ/kg, with the optimal operating pressure around 65 bar.