Terahertz (THz) wireless communication technology is one of the potential key technologies of the future 6G. It has aroused extensive attention at home and abroad. Firstly, the research plans and trends of 6G are introduced, and the features and advantages of THz wireless communication are reviewed. Then prospective scenarios as well as challenges of THz wireless communication applied in the future 6G are described. At last, action proposal towards 6G is suggested.