Since its implementation in July 2021, the “double reduction (the reduction of the excessive academic burden on primary and middle school students, and the over-heated off-campus tutoring)” policy (“the Policy”), which aims to foster a sound environment for extracurricular education, has attracted much social attention. At the preliminary stage where data and cases are insufficient, it is of theoretical and practical significance to evaluate extracurricular tuition and its effect mechanism before the Policy was implemented. This study analyzed the said question based on the data from the China Education Panel Survey between 2014 and 2015 (CEPS2014–2015) by virtue of propensity score matching (PSM) and the intermediate effect. The research found that: (1) extracurricular tuition (ET) is positively correlated with academic performance (AP); (2) high and low extracurricular tuition intensities (ETIs) show no difference in improving academic performance, and the group analysis shows that extracurricular tuition is influenced by the “optimal starting zone (OSZ)”; and (3) psychological resilience (PR) is an intermediate variable of extracurricular tuition, which acts as a “conversion valve”. Based on the above findings, the research raised the following suggestions. Firstly, we suggest to emphasize the promotion effect of after-class service on students’ academic performance and switch the functions of extracurricular tuition to after-sale service. Then, pay attention to the reverse effect of high extracurricular tuition intensity on students’ physical and psychological health and their academic performance. In practice, explore the effective “optimal starting zone” of extracurricular tuition for students. Lastly, cultivate students’ psychological resilience by shifting the core of education quality improvement from simple stacking of disciplinary knowledge to psychological health development.