Falling film absorption process is studied for the simulation of the absorber of the absorption solar cooling system. In this study, we use different absorbents such as lithium chloride aqueous solution, and mixed solutions of lithium and calcium chloride aqueous solution, and water is the refrigerent. We also discuss the effects of various parameters of the absorbents such as the solution flow rate (the Reynolds number), the solution inlet temperature and the absorber vapor pressure. The results of the present study can provide the design reference for the absorption solar cooling systems.