Objectives: The aim of this study was to explore the influence of learning social integration and self-doubt on the suicidal ideation, and to test the mediating effect of self-doubt and the moderating effect of drinking on suicidal ideation. Methods: A cross-sectional survey was administered to a convenience sample of 1,000 freshmen in a university in S city. A total of 803 questionnaires were included in the statistical analysis. To analysed the data, Pearson correlation and structural equation modeling were performed. Results: In this study, self-doubt had a mediating effects in the path way from learning social integration to suicidal ideation. Drinking had a moderating effect between self-doubt and suicidal ideation. Conclusions: The results suggest that the low level of learning social integration increases the level of self-doubt and leads to suicidal ideation. Drinking was a significant moderator of suicidal ideation. Therefore, interventions on various strategies to enhance academic performance and social interaction skill, and to help to stop or not to initiate drinking habit are needed in the early part of the freshman year.