The thermodynamic analysis of the integrated system was conducted and the indexes of the power recovery efficiency and the exergy efficiency were chosen for system performance evaluation. The impact of inlet temperatures of both the heat resource and cooling water on the power recovery efficiency and the exergy efficiency of the system were analyzed under certain initial conditions. The exergy loss and exergy efficiency of each component of the system were demonstrated which could direct the improvement target of the system for better heat transfer performance. When the heat resource inlet temperature t_h1=300℃, the power recovery efficiencies of the Kalina cycle (cooling water t_c1=25℃) and Rankine cycle (t_c1=15℃) are respectively 18.2% and 14.6%, the exergy efficiencies are respectively 41.1% and 33.1%, while the composite power recovery efficiency and composite exergy efficiency of the ammonia-water Rankine cycle are respectively 19. 6% and 46. 5%. Moreover, when the temperature of heating water is set as 70℃ or 90℃, while the temperature of back water keeps 40℃, the Rankine cycle can get additional 55.3% or 65.6% heating recovery efficiency or 8. 7% or 13. 4% heating water exergy efficiency.