Abstract: Vigorously promoting the development of renewable energy is an effective way to tackle the current energy crisis and environmental problems. Many counties and regions have already proposed their ambitious plans toward the transition to 100% renewable energy power systems（100% REPS）. Also, numerous academical advancements related to this area have been achieved in recent years. To provide an important reference for continuously conducting the future research work, this paper comprehensively reviewed the recent advancements and future trends in 100% REPS. First, we presented the definition of 100% REPS and its differences with the zero-carbon power systems and the 100% clean energy power systems, then key challenges in terms of technology, economy, and policy for building 100% REPS were analyzed. On this basis, a theoretical research framework was proposed, which covers six sections including the generation allocation, power grid expansion planning, reactive power configuration, stability analysis and control, operational dispatch, and power quality optimization. The difficulties and potential research contents in each section needed to be taken into consideration are revealed. Finally, future trends about the exploration and application of 100% REPS were summarized and prospected.