Abstract: The online teaching of the "Acoustic Testing" course which breaks the temporal and spatial limitations of teachers and students possesses important application value in remote training under special backgrounds. However, due to the lack of direct contact between teachers and students in the online course, there are certain problems in the stability of the teaching environment, the continuity of teaching links and the feasibility of practical teaching. A multi-dimensional online teaching platform, a closed-loop teaching system consisting of teaching, assessment, and continuous improvement, and a virtual simulation experiment project are constructed to accomplish the online teaching of ultrasonic testing experiment course. Thus, the main problems of online teaching of "Acoustic Testing" course have been solved to a great extent, and the online course has achieved good teaching results.