Abstract: Accident cause theory is the theoretical basis for recognizing the accidents and preventing recurrence of similar ones. Currently, there are a number of accident cause theories, including the accident causation sequence theory, but they all have some limitations in analyzing accident causes and cannot find problems in essence and achieve targeted prevention. So, based on analysis of accidents such as oil and gas pipelines and building structures, this paper puts forward a series of new basic principle of cause analysis, analysis process, and "tree type" simulation logic model, which can analyze the causes of accident according to the logic relationships of tree withering or dry stick breaking. This theory differs from the traditional one in the definition of the root causes, direct causes, and indirect causes of the accident as well as identification of content. This one is more systematic, avoiding the omission or deviation of accident cause, more favorable for the discovery of deeper causes of the accident and finding out the key to accident control. According to this theory, accidents such as some pipeline crack and the Sanfeng Building Collapse are analyzed to verify the applicability of this theory, which shows it has a leading edge in the analysis of accidents. This theory can provide a new set of theory and methods to the analysis of industrial structure failure accidents in the future.