The sudden outbreak of the epidemic made it impossible for universities to carry out traditional offline teaching in 2020, so universities developed online teaching practice. However, engineering design courses have their own characteristics, which makes online teaching unable to meet the requirements of the courses. So we take the urban design course in Nanjing University as an example, analyze it’s mission and purpose, considering that online teaching has the following problems, such as difficulty of site investigation, difficulty in deepening online teaching (the loss of space information expression, the failure of online communication between teachers and students), and the error in online oral defense. Accordingly, we carry out a systematic reform and innovation by the way of online site investigation（online site selection, online site investigation）, online educational reform (the use of VR technology, optimization of online communication), and online oral defense correction. All of this will provide useful experience for the future integration of online and offline teaching and the deepening of online teaching reform.