Abstract: Traditional graduate education focuses on theoretical teaching and the teaching is organized in a teacher-centered offline classroom,which has poor teaching effects and most graduate students feel disconnection between theory and engineering practice,thus being at a loss in solving practical engineering problems. And in most traditional bilingual classroom,teachers have to focus on vocabulary and sentence translation,which is not beneficial for graduates to improve their ESP. Aiming at these problems,a new teaching mode is explored to improve the teaching effects of this course. Firstly,the problems of traditional offline bilingual classroom and the advantages of the blended teaching are analyzed,and then the teaching design scheme of an online-offline blended case base teaching model for ground improvement is proposed from three stages of pre-class,classroom and after-class,and based on the existing cases,an example is taken to demonstrate the blended teaching mode. Finally,teaching effects of the new teaching mode is evaluated. The results show that the blended teaching model not only helps training and improving the ability of graduate students to solve practical engineering problems in complex environment,but also stimulates their interest in learning,improves their english skills,effectively evaluate their learning effects and improves teaching effect as well.