Objective: This study aims to explore the influencing factors of influenza vaccination in middle school students, and to provide a theoretical basis for improving the influenza vaccination rate and inform interventions. Methods: By using mixed research method, a combination of qualitative research and quantitative research, a survey was conducted among 9 145 middle school students selected from Beijing, Anhui, Shaanxi, Guangdong via the online survey using Wenjuanxing software. Multivariate Logistic regression models were used to analyze the influencing factors of influenza vaccination. After a purposeful sampling, 35 middle school students were invited for semi structured interviews and NVivo plus software were used for data analysis. Results: The self reported influenza vaccination rate of the middle school students was 38.2%. No experience of discussing an influenza vaccine with others ( OR=1.37, 95%CI =1.17-1.60) and devaluing the discussion about vaccination ( OR=1.30, 95%CI =1.08-1.57) was negatively associated with vaccination( P <0.05); The head teacher suggestion(OR=0.39, 95%CI =0.32-0.48), peers vaccination( OR= 0.29, 95%CI =0.25-0.33), and awareness of what the vaccine was and being able to explain it clearly( OR=0.68, 95%CI =0.61-0.75), discussing with others( OR=0.76, 95%CI =0.67-0.86), feeling the discussion is valuable( OR=0.66, 95%CI = 0.59- 0.73), being able to positively influence others( OR=0.61, 95%CI =0.55-0.68), being positively influenced by others ( OR= 0.62, 95%CI =0.54-0.71) were more likely to take vaccination via separated models( P <0.05). The interview results showed that the teacher s cognition and attitude towards the influenza vaccine could directly or indirectly affect the students vaccination decision, and the positive school opinion atmosphere may improve students vaccination rate. Conclusion It is suggested that the schools should increase students vaccination rate through head teachers guidance and organizing students to participate in discussion on influenza topics.