The organic combination of Internet of Vehicles and intelligent vehicles has produced Intelligent connected vehicle. Intelligent connected vehicle realizes the information exchange of people, vehicles and roads through on-board sensing system and information terminal, which is based on emerging technologies such as artificial intelligence and 5G communication technology. However, while the manufacturers integrate the emerging intelligent network technology into the car to bring convenience, rapidity, intelligence and comfort to customers, there are also many information security problems. This paper first introduces the booming trend of intelligent connected vehicles and the increasing security issues. While giving the definition and architecture of intelligent connected vehicles, the relationship between “intelligence” and “connected” and the differences in technical routes at home and abroad are compared. The current security threats faced by intelligent connected vehicles are summarized and analyzed. Combined with the technical architecture differences between intelligent connected vehicles and traditional vehicles, the attacks are divided into two categories: traditional attacks and new attacks, and the corresponding security defense countermeasures for each attack are given.Finally, the current research status of intelligent connected vehicles safety is summarized, and suggestions for the research direction of the current environment are put forward.