With the rapid development of multimedia technology, multimodal corpus came into being, which also opened up a new idea for oral English grammar teaching. In view of the problems existing in the current traditional English grammar textbooks, this paper applies the concepts of “corpus driven” and “multimodality” to grammar textbooks and tries to describe language use in a more authentic, reliable, and up-to-date form. In view of the problems existing in the current traditional English grammar teaching materials, this paper applies the semantic concept to the grammar teaching materials and tries to describe the language use in a more authentic, reliable, and up-to-date form. Based on the semantic concept, this paper studies the construction of college students’ oral English multimodal corpus. After the experiment, the results of the language fluency, accuracy, and complexity of the subjects in the experimental group and the control group are tested. The differences between the two groups were analyzed by one-way ANOVA as follows: in terms of language fluency, F   1 , 62 = 0.835 , P > 0.04 , which showed that there was no significant difference between the two groups after the experiment. In terms of accuracy, F   1 , 62 = 10.693 , P < 0.04 . There was significant difference between the two groups after the experiment. In this study, by analyzing and counting the distribution of conjunctions in students’ oral discourse, the types of conjunctions, their frequency of use, and the types of errors in use, we hope to understand the level and limitations of students’ use of conjunctions in oral discourse, so that students can better apply semantic conceptual cohesion and speak a coherent discourse, First of all, we should help students establish the awareness of textual cohesion and coherence.