As a fusion of various emerging digital technologies, the Metaverse aims to build a virtual shared digital space. It is closely related to extended reality, digital twin, blockchain, and other technologies. Its goal is to build a digital space based on the real world, form a virtual economic system, and expand the space of human activities, which injects new vitality into the social, economic, and other fields. In this article, we make the following contributions. We first introduce the basic concepts such as the development process, definition, and characteristics of the Metaverse. After that, we analyze the overall framework and supporting technologies of the Metaverse and summarize the status of common fields. Finally, we focus on the security and privacy issues that exist in the Metaverse, and give corresponding solutions or directions. We also discuss the challenges and possible research directions of the Metaverse. We believe this comprehensive review can provide an overview of the Metaverse and research directions for some multidisciplinary studies.