Due to traditional classroom teaching often being teacher centered, students passively receive knowledge and lack initiative and creativity. And classroom teaching is difficult to fully consider individual differences and learning needs of students, resulting in uneven teaching effectiveness. To address this issue, an evaluation of the effectiveness of an interactive teaching model for undergraduate English courses based on graph neural networks is proposed. Firstly, based on the application of graph neural networks, the evaluation indicators for undergraduate English classroom teaching are pre-set through the design of graph neural network model structure and the establishment of an evaluation index system for interactive teaching mode. Secondly, the design is completed in three steps: inputting the interactive teaching data indicators of undergraduate English courses into a graph neural network, constructing an evaluation model for the application effect of the interactive teaching mode, calculating the membership degree of the teaching effect, and evaluating the application effect of the interactive teaching mode of undergraduate English courses.