Taking the sintering waste heat utilization system of a steel corporation as an example,a general mathematical model of exergy efficiency for the entire thermodynamic system was established.The results of an exergy analysis calculated with the field test data show that the running exergy efficiency is only about 4.6%.In this consideration,the idea of grade recovery and cascade utilization of waste heat of sintering system was proposed,and the dual pressure waste heat power generation system was used for waste heat power recycle based on the exergy analysis of sintering gas.It results in an increase of exergy efficiency by 2~4 times of the original efficiency,and the waste heat utilization is improved greatly.The research results provide scientific basis for the entire sintering system’s design and reformation.