With the development of the digital economy, digital content has become an indispensable aspect of people’s lives. This book focuses on how to identify and manage harmful risk content within digital content. Based on internet technology and algorithm theory, integrating game analysis focusing on strategic interactions, the book provides a clear and in-depth introduction to the background, objectives, pathways, and measurement methods of digital content ecosystem governance.The book attempts to discuss the following questions with readers: 1) What complex content ecosystems do internet platforms face? What are the harms of this harmful content to society and the platforms themselves? What efforts have society and internet platforms made in response? 2) How are content risk control mechanisms constructed? How is the platform concept of freedom with responsibility implemented within them? 3) How do strategic interactions between various stakeholders influence the establishment of risk control mechanisms? And how can a practical path be found for implementation? 4) How are content risk control mechanisms gradually established and evolved at different developmental stages? What is the necessity of establishing a risk control platform? How can intelligent risk control strategies be combined with distribution strategies to generate greater utility?