In the context of severely restricted employment opportunities, undertaking an internship is an important way for students to enhance their employability and sustainable development. The aim of this study was to judge if the implementation of the Internship Promotion Programme (IPP) at universities in Zhejiang Province, China, could enhance graduates’ employability. We conducted surveys and interviews with 400 students and 100 business executives who participated in the IPP during the past 6 years. Based on the collected data and statistical analysis, the findings show that internships help students to improve their innovative thinking, interpersonal communication abilities (domestic and international), problem-solving skills, value creation and responsibility. Participants in the IPP were compared with students who did not take part. The results demonstrated that the IPP participants exhibited higher capabilities to perform important workplace tasks and that as a result, they became more attractive to employers. The analysis, therefore, demonstrates a positive correlation between the internship experience and employability. As a result, it can be concluded that the IPP improves students’ employability and is beneficial to enhancing the quality of higher education, and hence the sustainable development of students.