The current study employs a mixed-methods approach, integrating both quantitative and qualitative research, to achieve these objectives: (1) to develop a teaching manual for the mezzo-soprano part in opera for Chinese undergraduate music teaching, and (2) to evaluate and recognize the teaching manual designed for the mezzo-soprano part in opera for Chinese undergraduate music teaching. The study utilizes research methods such as literature review, performance observation, expert interviews, thematic analysis, and statistical evaluation to examine mezzo-soprano training comprehensively. The findings include a textual analysis of mezzo-soprano roles in Chinese and Western opera, expert feedback on the current situation of mezzo-soprano instruction, and an assessment of the newly developed teaching manual by five experts. This research contributes valuable insights to music teaching, providing guidance for both students and educators while promoting the development of bel canto vocal training in China. Additionally, the study highlights potential areas for further research, including expanding the range of examples and incorporating interdisciplinary content to enhance mezzo-soprano pedagogy.