In the context of industrial transformation upgrading, and mounting downward pressure on economy and the COVID-19 pandemic, whether the career planning of college students can improve their employment quality and promote the sustainable development of their career is an urgent issue. Based on an online questionnaire survey of university graduates of 2019 and 2020 from 23 universities in 9 provinces, this study, employing hierarchical analysis approach to construct the employment quality evaluation system of college students, analyzes the start-time and long-term impacts of college students' career planning on their employment quality and robustness. The study found that, overall, the earlier and more long-term their career planning is, the higher the quality of employment of university graduates. In order to further promote the quality employment of college students, the study suggests that colleges and universities at all levels need to set up a demand-driven career educational system, and clarify orientations of professional career education for counsellors. In addition, parents should also pay attention to the guidance of career planning for their children.