Learning engagement is an important factor to improve the quality of medical education. Exploring the level of medical students’ learning engagement and its internal mechanism is of practical significance to improve their academic achievement. The aims of this study were to investigate the relationship between achievement goal orientation, growth mindset and learning engagement of medical students, and explore the mediating effect of achievement goal orientation on growth mindset and learning engagement. A correlational cross-sectional study was performed using an online questionnaire. The study was conducted from February to March 2024 among 279 medical college students. General information questionnaire, the Mindsets Scale, Achievement Goal Orientation Scale and Learning Engagement Scale were used for investigation. Calculations were performed using Statistical Packages for Social Sciences 27.0 and Mplus 7.0. Descriptive statistics, correlation, and mediation effect analyses were used to analyze the data. A total of 279 valid questionnaires were finally recovered. The learning engagement score of medical students was (56.17 ± 13.01), growth mindset score was (11.26 ± 3.37). The approach goal orientation played a partial mediating role between growth mindset and learning engagement in medical college students. Growth mindset can influence learning engagement through achievement goal orientation. Medical college educators should pay attention to the cultivation of students’ growth mindset and enhance their learning engagement. The verification of the mediating effect of approach goal provides data support for formulating relevant intervention measures.