5G is the fifth-generation mobile networks. It has the characteristics of fast transmission, high bandwidth and low latency, which is beneficial to the development of smart campuses. In recent years, the rapid development and deployment of smart technologies such as 5G, Internet of Things, augmented reality/virtual reality/mixed reality/cross reality, artificial intelligence, cloud computing, blockchain, and quantum computers have made smart campuses fully advanced and improved, making great strides towards the 5G smart campus. In the future, the rise of 6G and quantum computers will bring the development of smart campuses into a new world. Smart campuses have become a policy focus of international technology development. This article specifically explores and explains 5G smart campuses, key technologies and future prospects for the reference of educational authorities and schools at all levels in the development of 5G smart campuses.