Although research has consistently highlighted the importance of school adjustment for high school students, validated tools for assessing this construct are currently lacking. To address this gap, our study aimed to develop and validate a scale to measure school adjustment among high school students. Employing a two-stage approach, we first examined the concept of adjustment and generated scale items. Subsequently, we surveyed 1121 high school students, and randomly split the data into two groups for subsequent analyses. Through exploratory in the first stage and confirmatory factor analyses in the second stage, we identified two higher-order factors within the scale: social adjustment and academic adjustment, with academic adjustment consisting of two sub-factors, academic performance and, academic engagement. The results indicated that the scale has an excellent model fit, as well as adequate reliability and high construct validity. Overall, our study provides a valuable tool for assessing school adjustment in high school students.