This study aims to examine the effectiveness of an intervention program based on the PROSPER, a comprehensive framework which emphasises the importance of "positivity," "relationships," "outcome," "strength," "purpose," "engagement," and "resilience" in pre-service teachers' well-being in Hong Kong. Participants were pre-service pre-school teachers (N = 77) who participated in a 1-month randomised control trial with four intervention workshops. They were randomly assigned to either intervention (n = 40) or wait-list control conditions (n = 37). A survey with measures that assessed PROSPER well-being components was administered to participants before and after the intervention. Findings of repeated measures "MANCOVA" revealed no significant time x group interaction effect, Wilks' Lambda "F"(7, 50) = 1.66, p = 0.14, [eta-squared] = 0.19. Results of univariate analyses showed that a significant time x group interaction effect existed in relationship component ([eta-squared] = 0.08), indicating that the intervention was effective in facilitating pre-service pre-school teachers' positive relationships with their peers. Findings underscore the potential benefits of designing positive psychological interventions for teachers amid the COVID-19 pandemic.