College students' graduation projects reflect their teamwork abilities. The current research develops a practical framework and causal model of knowledge-sharing behavior, cohesion, and team performance for design college students in Taiwan. Using survey data collected from 115 students who completed their graduation projects in a design college, PLS-SEM was run to test the model. In addition, 11 students who were on teams that won competitions or were shortlisted were interviewed. Results found that knowledge sharing has a significant positive effect on team performance, and cohesion has a significant positive effect on both team performance and knowledge sharing. The students with high cohesion often exhibit knowledge sharing behaviors and excellent team performance. These findings suggest project supervisors should induce knowledge sharing behaviors during the graduation project process in order to enhance student group cohesion.