Abstract: Mixed reality technology has made remarkable progress during the past two decades and shows significant development prospects. As the crucial support of mixed reality, human-computer interaction hits the research area in the world. Over the years, simple, natural and effective interaction modes have always been the focus of human-computer interaction in mixed reality. Centering on the development tendency in recent years, this paper mainly discusses human-computer interaction design principles and evaluation methods as well as key technologies in mixed reality, surveys applications of different interaction techniques in mixed reality, finally makes a summary and puts forward the existing problems.