<p>Adolescents, while morally malleable, are susceptible to negative factors that can lead to moral shielding due to their ongoing physical, mental, and social development. Moral shielding creates a range of psychosocial problems that determine the trajectory of the adolescent’s moral development. However, the intangible nature of moral shielding makes it challenging to define and measure systematically. This study aims to develop a comprehensive measurement tool for adolescent moral shielding and to provide a foundation for future research on its factors and developmental trajectories. Study 1 was based on decision-making process theory to develop 25 items through interviews with students and school’s moral management teachers, validated by experts, resulting in an initial questionnaire with 24 items. Study 2 (<i>N</i> = 370) focused on item analysis, exploratory factor analysis, and reliability analysis to refine the questionnaire structure. Study 3 (<i>N</i> = 339) conducted a confirmatory factor analysis on the initial version of the questionnaire, resulting in a questionnaire containing 16 items. Study 4 (<i>N</i> = 437) used moral identity, moral defense, and pro-environment behavior scales as criteria for a validity analysis to establish criterion-related validity. The results showed that the moral shielding questionnaire for adolescents contains four dimensions, namely, moral identification desensitization, moral judgment inaccuracy, moral intention imbalance, and moral behavior deviation, with a total of 16 items. The questionnaire can be used effectively to measure adolescent moral shielding.</p>