Rulebased morality is a crucial concept in shaping the professional ethics and integrity of teachers in the new era. It aims to transcend the dichotomy between rules and ethics, achieving a harmonious blend of internal self-discipline of professional ethics and external regulation of rules. This approach offers a fresh perspective for enhancing and refining the development of professional ethics and integrity among teachers in the new era. Rule-based morality is vital for ensuring teachers’ smooth transition from being seen as “saints” to “professionals,” enabling them to embrace their “specific role” distinct from the “general social role,” and ensuring a dialectical unity of “freedom” and “norm” for teachers. To enhance the efficacy of instilling virtue through rules in the new era, efforts should focus on optimizing the top-level design of the rule system governing teachers’ professional ethics, refining its systematic construction, and emphasizing its practical application.