Abstract: Large quantities of waste heat from medium and high temperature flue gas are generated from industrial kilns. However,the present power cycles or working fluids is difficult to effectively recover the waste heat of flue gas with the temperature drop. A cascading transcritical power cycle using CO_2 as working fluids was proposed. The maximum net power output per unit mass flue gas was selected as objective function. The effects of parameters on cycle thermodynamic performance were investigated under flue gas temperature of 400 and 500 ℃ .The influence of mass split flow ratio and high pressure on thermal matching in regenerator and cycle performance were mainly analyzed. The optimization and comparative analysis was conducted among basic transcritical cycle,regenerative transcritical cycle and cascading transcritical cycle. The results indicate that the thermal matching in regenerator is key influence factor on cycle performance of the cascade cycle. By adjusting mass split flow ratio x at the outlet of the working medium pump to improve the regenerative matching,the optimal value of of working medium is 0.6 and 0.7 under flue gas temperature of 400 and 500 ℃ . The increase of endothermic pressure is beneficial to the increase of net power output,and when the endothermic pressure increases from 20 MPa to 35 MPa under flue gas temperature of 500 ℃,the net power increases from 117.4 kW to 143.8 kW,with an increase of 22.49%. The higher pressure also promotes power output for both high-and low-temperature turbines,but the deteriorates heat exchange amount in regenerator. The ratio of low-temperature turbine power output to total ranges from 31.4% to 27.3% with high pressure increasing from 20 to 35 MPa,which means that the hightemperature turbine is more affected by high pressure. Compared with the three transcritical CO_2 cycles,the basic transcritical cycle has the lowest thermal efficiency and net power output. The regenerative transcritical cycle achieves the highest thermal efficiency. The cascading transcritical cycle outputs the maximum net power. The net power output of cascading transcritical cycle is 22.2% and 6.1% higher than that of basic and regenerative cycle under flue gas temperature of 400 ℃,respectively,and the values is 35.7% and 12.5% under flue gas temperature of 500 ℃ .