With independent temperature and humidity control, desiccant air-conditioning (DAC) systems have multi-aspect advantages (e.g., high-efficiency moisture control, no ozone-depleting coolants use and easy renewable integration etc.) compared with conventional vapor-compression cooling systems, thereby attracting increasingly more research attention. Recently, many studies have been conducted to improve DAC system overall performance by integrating various energy sub-systems/technologies, improving system configurations and optimizing system designs and controls. This study, therefore, provides a timely and systematic review on the abovementioned studies. The study first overviews three typical DAC system configurations, their operating processes, and the commonly used performance indicators. Second, the study summarizes the main integration approaches of DAC systems. Detailed comparative analysis has been provided regarding these integration approaches. Third, the study presents the DAC system configuration improvements in four main categories, and comparatively analyzes their performance enhancements. Last, the study briefly reviews the DAC system design and control optimizations. Meanwhile, based on the DAC system latest developments, the study provides discussions on pressing issues and recommendations for future works. The study can help improve the understanding of the latest developments on DAC system integration and design for overall performance improvements. Associated discussions and recommendations may help focus the needed efforts on solving the pressing issues and outstanding problems, thereby leading to DAC system further performance improvements.