This article argues that 2025 constitutes a critical node at which China's publishing sector upgrades from "digital transformation" to "in-depth digital transformation". The key claim is that the new stage cannot be achieved through superficial tool adoption alone; it requires structural confrontation with deep dilemmas and targeted reengineering across service logic, professional capability, and organizational form. The analysis therefore organizes its argument around a diagnostic–pathway architecture: three structural dilemmas define the transformation situation, and three reengineering pathways constitute the transformation response. The diagnostic portion identifies three structural dilemmas. The identity dilemma refers to a mismatch between legacy publishing identities and the demands of the in-depth digital stage: when publishing is treated as a distribution-centered function, it struggles to meet expectations for continuous, data-informed operation. The production dilemma names a structural tension in how publishing outputs are created and iterated: production structures optimized for traditional modes are misaligned with the demands of iterative, service-oriented publishing. The management dilemma describes constraints in governance and coordination: in-depth digital transformation raises requirements for cross-functional coordination, faster response cycles, and the integration of multiple capabilities, which legacy management structures may fail to provide. To address these dilemmas, the paper proposes three reengineering pathways: reengineering of publishing services, reengineering of publishing professions, and reengineering of publishing organizations. Publishing service reengineering is framed as a paradigm-creating move that reshapes publishing's value proposition. It proposes that mass publishing should turn toward immersive leisure publishing services; educational publishing should turn toward personalized learning publishing services; and professional publishing should turn toward knowledge-payment publishing services. In this scheme, service reengineering is not an add-on but a new role definition that aligns publishing with diversified user needs and new consumption rhythms. Publishing profession reengineering then targets capability reconstruction, implying that professional work must adapt to the operational requirements of service-oriented publishing. Publishing organization reengineering focuses on structural vitality and governance fit, implying that organizational design must support the transformational demands that identity, production, and management dilemmas expose. The paper further argues that publishing innovation is the fundamental driver of this transformation and specifies three domains of innovation as its core: content innovation, format (business-form) innovation, and management innovation. By locating innovation as the mechanism that turns "trend" into "reality, " the article constructs a forward-looking narrative that transforms descriptive trends into an actionable transformation logic. The overall conclusion is that upgrading to in-depth digital transformation is both an inevitable trend and an urgent task. By confronting structural dilemmas and executing reengineering pathways, publishers can create new paradigms in mass, educational, and professional publishing, thereby enabling the sector's transition toward a more resilient and adaptive future stage.