The rapid development of the multimedia era requires that education and teaching can make full use of multimedia technology. This paper applies interactive multimedia technology to vocal singing teaching in colleges and universities, and constructs an interactive multimedia vocal singing system to provide technical support for diversified vocal singing teaching modes. The singing scoring module of the system uses the vocal music measurement method based on the comparison of audio characteristic parameters, and the scoring mechanism calculates the objective evaluation score according to the degree of similarity. Students majoring in vocal music in a university are selected and the teaching practice effect is used as a means of verification. The comprehensive teaching effect and comprehensive ability scores of the observation group students using the vocal singing teaching system were significantly higher than those of the control group students using traditional vocal singing teaching methods. Meanwhile, the mean values of the operability and interactivity of the vocal singing system in the observation group were 24.96, 24.63, 24.26, 24.61, respectively, highlighting the fact that the vocal singing teaching system designed in this paper is also generally welcomed by students in the process of improving their professional ability in vocal singing. The application of interactive multimedia vocal singing teaching system will significantly promote the development of diversified vocal singing teaching mode in colleges and universities.