In early 2020, novel coronavirus pneumonia outbroke worldwide. Under the requirement of the Ministry of education, online teaching has received unprecedented attention. Therefore, how to ensure the quality of online teaching and ensure the learning effect of students has become the teaching difficulties during the epidemic period. Taking the port, waterway and coastal engineering specialty of Tongji University as an example, the online teaching practices including the platform selection, organization arrangement, assessment method and quality management are presented, and the online teaching quality assurance system concerning "platform selection putting emphasis on effect, teaching organization on training, student assessment on process and practice link on guidance" is put forward. Meanwhile, based on practical teaching, the difficulty in online teaching is summarized and its solutions found, which can provide reference for online teaching of port, waterway and coastal engineering specialty specialty in the future.