With the increasing demand for high-quality compound talents in society, the scale of graduate enrollment continues to expand, and the diversity of graduate enrollment types develops. The limitations and deficiencies of traditional single-tutorial graduate training gradually appear. In view of the main problems existing in the process of postgraduate training in recent years, this paper analyzes the relationship between the number of postgraduates reported and the change of tutor composition structure from the aspects of postgraduate training system and teacher-student structure, and expounds the importance of the reform of postgraduate training system. On this basis, it puts forward the reform method of postgraduate tutor team construction mechanism. Through the analysis and optimization of tutor research direction composition, tutor age echelon and team regular meeting system in the graduate tutor team, we can achieve the goal of more efficient graduate management, more diversified innovative thinking cultivation and more personalized graduate cultivation. The research results can provide reference for the reform and practice of large team graduate cultivation system.