Objective: This study aimed to assess the effects of a multi-component positive psychology intervention on psychological well-being (i.e., autonomy, environmental mastery, positive relationships, purpose in life, personal growth and self-acceptance) outcomes among pre-service preschool teachers in Hong Kong.Method: Participants were pre-service preschool teachers (N=67, Mage=21.45, SD=3.46, nfemale=95.3%). They were randomly assigned into the intervention group (n=34; who received four intervention workshops and a theory-driven mobile phone application) and waitlist control group (n=33; who received intervention materials after completing the data collection). Participants completed a survey that measured their psychological well-being at baseline and two months later. MANCOVA and ANCOVA were used to examine the intervention effects by adjusting for sex and age.Results: MANCOVA results showed no significant multivariate group x time interaction effects of the intervention on psychological well-being, Wilks’ Lambda F(6,58) =2.04, p=.07, η2=.17. However, in the results of ANCOVA, significant group x time interaction effects were found in environmental mastery, purpose in life, personal growth, and self-acceptance (η2=.09-.14, p<.05). The results showed that the intervention group scored significantly higher on those variables than the control group over time.Conclusion: The multi-component positive psychology intervention is a promising way to promote four dimensions of pre-service teachers’ psychological well-being. Positive psychology training (e.g., introduction of growth mindset, SMART goals, psychological needs support) can be included in teacher education to equip the pre-service teachers with positive psychological skills/mindset before entering the stressful teaching environment. Copyright © 2022 European Conference on Education.