In the process of applying traditional teaching forms, problems such as low participation in classroom activities and poor independent learning are gradually highlighted. This paper first designs the task-based cooperative language acquisition model then constructs the supervision and management system for cooperative learning, and finally establishes the evaluation mechanism for task-based cooperative learning. This paper uses the questionnaire survey method, Pearson correlation coefficient method, principal component analysis method, and multiple regression analysis methods as data analysis methods. By establishing a mathematical model, the parameters to be estimated are listed, and then these data are fitted, and finally, a statistical analysis is performed. Through the questionnaire survey method, this paper verified that the method had a positive effect on students’ Japanese learning; 46.2% of students enjoyed learning Japanese, and 92.3% participated in group discussions. The effectiveness of Japanese language teaching was assessed by extracting three main factors through principal component analysis, which were summarised as pre-study performance, classroom performance, and individual thinking performance. Under the language acquisition model, teachers can improve students’ learning effectiveness by monitoring and encouraging their performance on these three indicators.