Previous studies on international Chinese education have focused mainly on adults’ Chinese learning, but there is limited discussion on adolescents’ learning. With the progress of science and technology, the multimodal teaching mode has attracted the attention of the academic circle in recent years. This paper selected the vocabulary teaching for adolescents in the demonstration course of the elementary-level comprehensive course of international Chinese education and used the software ELAN5.9 to annotate and calculate the various modalities used in teaching. This study shows that in Chinese vocabulary teaching for teenagers, the main modality is the auditory mode; that is, speech is the main part, followed by the visual mode. The teacher often used pictures and cards to assist teaching. In the kinesthetic mode, the teacher mainly used gestures and instructions were given through the cooperation of gestures and body language. Finally, in the environmental mode, the teacher only showed social and personal distance with students in group activities. This is reflected in the teachers’ walk in the classroom and participation in group discussions to observe and correct students’ language output. This research further analyzed how the teacher used multiple modalities’ coordination in vocabulary teaching and proposed teaching suggestions. This study can provide references for the application of multimodal discourse analysis in the field of international Chinese education.