Abstract: In review of the current situation and future of research and application of metaverse, this paper focus on four aspects: theoretical concepts, key technologies, application scenarios and policy governance. The academic community has now formed three major theoretical perspectives: parallel universe view, fusion universe view and evolutionary universe view, which converge three technological development paths of replicated reality, augmented reality and transcendental reality, respectively. The digital economics in business life, industrial production, culture and education, and urban society have produced a positive weather of blossoming. In terms of governance, this paper suggests that the development of metaverse in China should be built with "autonomous and controllable" industry, "virtual-reality interaction" direction and "inclusive and prudent" attitude. Finally, this paper presents three basic metaverse indicators, namely metaverse index, metaverse duration and metaverse population, to characterize the space, time and development of metaverse respectively.

Key words: Metaverse, Virtual reality, Augmented reality, Decentralization, Digital human, Digital economy, Smart governance