Abstract: With the development of the Internet of things technology, smart home industry has become increasingly prosperous, and its security issues have attracted the attention of more and more researchers. Currently, the related research on smart home security is still in initial stage. This paper first reviews the development history and current status of smart home, and summarizes the architecture of current smart home system. In terms of security, we analyze and summarize the domestic and foreign literatures in recent years, and divide security issues into three aspects: platform security, device security and communication security. Platform security research mainly focuses on designing secure authentication and access control scheme, as well as discovering security issues in new scenarios such as smart home trigger-action and smart speakers; device security research mainly includes device firmware vulnerability discovery and side channel analysis; communication security research mainly includes protocol vulnerability discovery and network traffic analysis. Through in-depth analysis of the shortcomings of existing research work, the challenges and opportunities faced by smart home security are summarized. Finally, based on the current research status of smart home security, we point out four future research directions.