The invention discloses a liquid desiccant air conditioning system and a structure thereof. The liquid desiccant air conditioning system comprises a compression refrigerating system and a liquid desiccant system and is characterized in that the compression refrigerating system is composed of one or more independent refrigerating systems including the first compression refrigerating system and the second compression refrigerating system; the liquid desiccant system comprises a desiccant device and a liquid regenerator; the first compression refrigerating system is responsible for cooling of the desiccant device of the liquid desiccant system, and the refrigerating capacity of the first compression refrigerating system is decided by the refrigerating capacity of the desiccant device; the second compression refrigerating system is responsible for reheating the liquid regenerator of the liquid desiccant system and dealing with precooling of air, and the refrigerating capacity of the second compression refrigerating system is decided by the regenerated heat of the liquid regenerator; and by utilizing the cyclic utilization characteristics of the compression refrigerating system and the liquid desiccant system, the problems that cold and heat of the liquid desiccant system are mismatched, and the liquid desiccant system needs water supplying are solved, energy consumption is reduced, and the overall efficiency is improved.