Firstly, the necessity of case database construction was put forward through analyzing the teaching goal and present teaching situation of the engineering ethics course for postgraduates with professional degrees in engineering universities. Secondly, the case database of engineering ethics in municipal engineering field was constructed based on the five sub-fields such as water supply engineering, wastewater engineering, building water supply and drainage engineering, water supply and drainage pipe network and ecological restoration of water environment. Finally, the value of the case database construction was explored through its teaching practice and teaching feedback.The results showed that the case database of engineering ethics in municipal engineering field promoted the reform of the training mode of professional degree postgraduates, which could activate the classroom atmosphere and increase the frequency of mutual interaction between teachers and students. It also promoted students to understand deeply, master theoretical knowledge and apply it to engineering practice flexibly, thereby effectively improving their integration capability of combing theory with practice. Thus, it is of great significance for professional degree postgraduates in the municipal engineering field to improve the engineering ethics consciousness and fulfill social responsibilities actively. In addition, it also can provide references for other professional degree postgraduates in the case database construction and teaching practice.