The low thermal efficiency and low economic benefits of power generation systems under small temperature difference conditions have always hindered their practical operation. In order to explore effective ways to achieve performance optimization of thermodynamic cycle electrical power generating systems under small temperature difference conditions, this study constructs a static analysis model of an organic Rankine cycle with small temperature difference, selects six different commonly used refrigerants, and investigates the influence of key parameters on the thermodynamic and economic performance of the system using difference working fluids. The outcomes indicate that key parameters such as evaporation temperature and condensation temperature play a critical role in the thermodynamic and economic performance of the power generation system. For the working fluids, R227ea provides the highest net power output, while ammonia (R717) is the best performer in regard to system thermal efficiency and economic performance.