To better understand the latest development of renewable energy systems, recent studies on multi-energy complementary power systems with a high proportion of renewable energy are reviewed in this paper. The connection modes of power grids and economic system analysis are summarized and discussed respectively, putting forward some suggestions on the system design and operation optimization. Firstly, the characteristics and differences between an integrated system and an off-grid system are reviewed, concluding that an integrated system is more reliable and costeffective based on a few case studies. Secondly, the commonly used economic parameters and cost evaluation methods of the hybrid power system are reviewed. Those methods offer crucial tools to optimize the system, and they are able to analyze the system feasibility, enabling the most economical configuration. The results of several cases prove that the hybrid multi-energy system is more economical than the single-energy system. Finally, there are few articles focusing on technical details assessments and environmental impacts, which leaves room for future study.