This white paper mainly introduces the Huawei Cloud federated learning solution and comprehensively introduces federated learning from the perspective of theory, practice and application. From the theoretical perspective, the concepts, classifications, advantages, challenges and research status of federated learning are introduced; from the practical perspective, the architecture, features, functions and application scenarios of the Huawei Cloud federated learning platform are introduced; from the application perspective, the federated learning is introduced in government, financial, medical, manufacturing, retail and other industries. Application practice.