Based on the important situation that interdisciplinary research can promote the development of research productivity, the paper analyses the effects of the national support of interdisciplinary research, the interdisciplinary research management system, operation mechanism and evaluation mechanism, the interdisciplinary research organizations and the contact between the interdisciplinary research organizations and the industry on the promotion of interdisciplinary research productivity in research universities as well as the underlying mechanism. The hypotheses are tested through the regression analysis of 203 questionnaire samples. The results indicate that there is no significant effect of the national support of interdisciplinary research on the promotion of interdisciplinary research productivity in research universities, there are significant, very significant or extremely significant and positive effects of other elements on the promotion of interdisciplinary research productivity in research universities. The interdisciplinary research evaluation mechanism has the greatest effect on the promotion of interdisciplinary research productivity in research universities, followed by the interdisciplinary research management system, the interdisciplinary research operation mechanism, the contact between the interdisciplinary research organizations and the industry, and the reasonable interdisciplinary research organizations.