This book discusses the theory of the space fault tree framework, which is primarily used internationally for system reliability analysis. Through the integration of the factor space theory and the theory and method of intelligence, space fault tree can be used in intelligent analysis and big data processing. This book focuses on continuous space fault tree, discrete space fault tree, inward analysis of system factor structure, function structure analysis, system reliability with respect to influencing factors, cloudization space fault tree, cloud similarity, and clustering analysis and similarity.