The global 5G communication network subscriber base has surpassed 400 million as of May 2021, thanks to the commercial deployment of 5G communication technologies around the world. Research on the next-generation wireless communication technologies has been conducted to address the demand for ultrahigh data rates and ultralow latency for future applications. The large number of absolute bandwidth resources in the terahertz band is the most significant advantage of the terahertz communication, making it suitable for various applications. Herein, the relevant research in the field of terahertz communication is described. First, we introduce the plan and vision of 6G communication network, as well as the current status of the terahertz communication technology on a domestic and worldwide scale. Second, the key terahertz communication technology and potential application scenarios are discussed. Finally, we present a summary of the current research results and an outlook on future research directions to provide new ideas for moving into the “terahertz era.”