The invention discloses a 
gas transmission pipeline leakage detection 
system and method suitable for multiple state changes. The 
gas transmission pipeline leakage detection 
system and method suitable for the multiple state changes comprise a 
gas transmission pipeline leakage detection 
system (system for short) suitable for multiple state changes and a gas transmission pipeline leakage detection method (method for short) suitable for the multiple state changes. The system comprises an input module, a gas transmission pipeline transmission mechanism model, a neural network compensation model, a pipeline system 
signal collection module, a correction output 
processing module and an error obtaining module; the method aims at building a gas transmission pipeline 
mathematical model, obtaining a gas transmission pipeline state-space equation, 
processing flow signals of the gas transmission pipeline state-space equation, building the RBF neural network and verifying a detection model; the gas transmission pipeline flowing 
mathematical model and the detection method based on knowledge are combined, 
tail end loads, the pipeline 
diameter, pipeline bending, the environment temperature, the gas 
wave velocity, a compression coefficient, the pipeline hydraulic 
frictional resistance coefficient and the like are researched, and the gas transmission pipeline leakage is monitored; and a pipeline model is trained, and an accurate model suitable for the pipeline condition changes is obtained.