Social and emotional skill is the cornerstone of success and happiness in life. In 2021, the global first test of SSEs (Study on social and emotional skills) provides a solid data foundation for the international comparative study of adolescents’ social and emotional skills. Using DEA (data envelop analysis) method, taking class size, teacher education, sses training, sses measures and campus activities as input variables and five skills as output variables, this paper evaluates the training effectiveness of 1,171 primary and secondary schools in 10 cities participating in the international evaluation. The results show that: first, the social and emotional skill training effectiveness of primary and secondary schools in all cities is generally high, and the average value of primary school is more than 0.8. The average value of middle school is above 0.9. Second, at the primary school stage, Suzhou schools have achieved outstanding results, not only the highest average, but also a high-level balanced type as a whole. In the middle school stage, Istanbul is the city with outstanding training results, which is also a high-level balanced city. Third, there are 82 high-performance primary schools and 87 high-performance secondary schools in all cities, of which Istanbul and Bogota account for a large proportion. Fourth, sense of belonging to school is the most important factor to improve the social and emotional training effectiveness. According to the above research results, this paper suggests that we should strengthen international cooperation and empirical research on social and emotional skill, look for gaps and fill in weaknesses while summarizing the successful experience of Suzhou, and take high-quality balance as an important goal of social and emotional ability training in primary and secondary schools in China.