Climate variability and staff mobility have exacerbated the vulnerability of the indoor environment, which calls for air-conditioning units capable of adapting to the active regulation demand of the changing heat and humidity loads. The identification of the refrigerant constitutes an essential sector of the air-conditioning system design. A composition-adjustable dual cooling source (CADCS) chiller has been proposed utilizing the characteristics of inefficient condensation of the non-azeotropic mixture. Separated flows of the working fluid with flexible mass fraction and flow rate respectively treat the waste heat and moisture. Multi-criteria screening mechanism for the working fluid is established involving: i) application field. The critical temperature is better restricted within 300 K to 400 K for application in air-conditioning. ii) environmental impact. The GWP of the candidate cannot exceed 800. iii) cycle architecture adaptability. The boiling point difference preferably exceeds 20 K. iv) liquid separation potential. The obvious temperature glide and substantial separation range allow for the integration of liquid separation technology. Thermodynamic performance optimization indicates that propane/isobutane outperforms all the candidates at a mass fraction of 0.5:0.5 characterized by obvious temperature glide and close to temperature change of the heat transfer medium. The maximum coefficient of performance (COP) is found to be up to 5.2 for the BDCS cycle and 4.42 during separation at vapor quality 0.436 for the CADCS cycle. The exergy loss of the evaporator is reduced by 17.1 %-73.7 % while the exergy efficiency is improved by 3 %-59.7 % due to temperature match refinement in the CADCS cycle. The refrigerant charge in the CADCS cycle can be saved by 5.54 %-15 %. The accumulating waste heat demands a lower vapor quality during separation, while the moisture load barely exerts an effect. Moreover, the effect of the subcooling degree on the cycle performance is analyzed and suggested at 1 °C. The CADCS cycle constitutes a promising prospect of dynamic treatment for thermal and humidity load in the air-conditioning room due to its flexible function and improved heat transfer match.