According to the training goal of underwater acoustic engineering in Information Engineering University, we find the characteristics of underwater acoustic communication systems, summarize the experience during the years of teaching students practice, and then propose the teaching method of "underwater acoustic communication system" course, which is  summarized as "4Rs". This paper firstly describes the meanings of "4Rs", which is suitable for our students. Then, we show the teaching contents and what the students can learn. And finally, we tell the  implementation ideas of 4Rs teaching method, and through the consecutive practical teaching training, we can have many favorable teaching results.