A significant amount of low-grade waste heat is discharged during industrial production processes. Utilizing heat pump technology to upgrade and reuse this waste heat can effectively reduce carbon emissions associated with industrial operations. When recovering industrial waste heat using heat pump systems, considerable temperature variations occur at both the heat source and heat sink sides, leading to pronounced irreversible losses. Non-azeotropic refrigerant mixtures exhibit a temperature glide during phase change, which enables better thermal matching within heat exchangers and consequently reduces irreversibilities in the heat transfer process. This study analyzes multiple refrigerants based on the characteristics of non-azeotropic mixtures and proposes a novel blend tailored for industrial waste heat recovery, guided by the principle of complementary advantages. Furthermore, a simulation model of a centrifugal high temperature steam heat pump for large-scale industrial waste heat recovery is established. The system performance of the selected non-azeotropic refrigerant mixture is compared with that of the conventional refrigerant R245fa under various conditions, including different condensation temperatures, waste heat flow rates, and heat source temperatures. The results show that the selected non-azeotropic blend R600a/R1234ze(Z)/R1336mzz(Z) in a molar ratio of 30%/20%/50% exhibits superior thermodynamic performance compared to R245fa. Under constant heat source conditions, the optimal condensation temperatures for R245fa and the mixed refrigerant are 107.5℃ and 110℃, respectively, with corresponding system coefficients of performance (COPh) of 3.36 and 3.94. At a condensation temperature of 110℃, the COPh increases by 20.45%. When the heat source conditions vary, the compression ratio is reduced by over 18%, and the COPh improves by 19.31% compared to R245fa, demonstrating the notable energy-saving potential of the proposed refrigerant mixture. Additionally, the study reveals that variations in heat source temperature have a more significant impact on system performance than changes in waste heat flow rate. These findings provide valuable insights for the selection of refrigerants and the operational optimization of high-temperature steam heat pump systems.