Objectives <p>This study aimed to develop and preliminarily validate a blended (online–offline) Mindfulness-Based Stress Reduction (MBSR) curriculum tailored to junior high school teachers. It sought to address gaps in existing MBSR programs, including insufficient contextual adaptation to teachers’ unique stressors, limited integration of digital tools, and a lack of empirical validation for secondary education settings.</p> Method <p>Guided by the ADDIE (Analysis, Design, Development, Implementation, Evaluation) model and a whole-pathway intervention framework, the curriculum was refined via three rounds of expert review (<i>n</i> = 3, specializing in psychology and education). A quasi-experiment was conducted with 59 junior high school teachers, randomly assigned to an experimental group (<i>n</i> = 28, 4-week blended MBSR intervention using the “Qingxi” APP and offline sessions) or a control group (<i>n</i> = 31, no intervention). Outcome measures included the Mindful Attention Awareness Scale (MAAS) and the Occupational Stress Questionnaire, with pre- and post-test data analyzed using independent-samples <i>t</i>-tests.</p> Results <p>The final curriculum included four weekly thematic modules (self-acceptance, student care, colleague connection, work engagement) and supporting tools. Post-intervention, the experimental group showed a significant reduction in occupational stress and a dramatic increase in mindfulness. The control group showed no meaningful changes in stress or mindfulness.</p> Conclusions <p>The blended MBSR curriculum is effective in reducing occupational stress and enhancing mindfulness among junior high school teachers. Its innovations—contextual alignment with teachers’ work realities, precision integration of digital tools, and condensed 4-week format—address key limitations of traditional MBSR programs. The curriculum offers a scalable, cost-effective solution for teacher well-being in educational settings.</p>