Specifically，in China, to contain the COVID-19, the Chinese government has banned most-face-to-face activities, including teaching. The Chinese Ministry of Education has launched an initiative entitled “Disrupted Classes, Undisrupted Learning” to provide flexible online learning to hundreds of millions of students from their homes. Inspired by the united solidarity and innovative experiences of millions of teachers and students, this handbook aims to define the term “flexible learning” with vivid examples and touching stories. It describes several implemented flexible online learning strategies during the COVID-19 outbreak. These strategies are presented based on six dimensions, namely (a) infrastructure, (b) learning tools, (c) learning resources, (d) teaching and learning methods, (e) services for teachers and students, and (f) cooperation between enterprise, government, and schools. Specifically, this handbook can help other educators, researchers and practitioners implement similar case studies in their context. Finally, this handbook shows, based on this practical experience, different collaborations between several sectors (governmental, telecommunication, enterprise, etc.) to provide effective and inclusive education in case of emergencies, such as the COVID-19.