Educational systems that are capable of supporting and including all diverse cultures is crucial in the modern era of sustainable globalisation. Our main objective is to examine science teacher training for the 21st century and how to integrate cultural ideas to cultivate educators with a global perspective. Our study designed professional development program grounded in culturally relevant pedagogy that was conducted from January 2022 to January 2024 at Shanghai High School involving 150 teachers. The findings showed significant positive impacts on both student learning outcomes and teacher self-efficacy. Paired-samples t-tests showed a substantial increase in student science test scores following the program (p < 0.001), with a moderate effect size (Cohen's d = 0.47). Furthermore, linear regression analysis indicated a positive association between teacher self-efficacy at baseline and student test score gains, suggesting that teachers with higher initial confidence in CREST strategies fostered greater student learning improvements. The program also yielded positive effects on teacher self-efficacy in CREST strategies over time. ANOVA demonstrated statistically significant increases (p < 0.05) in all four CREST areas (Content Readiness, Equity Readiness, Information Analysis, and Use of ICT) from baseline to both 1 year and 2 years post-program.