Abstract: The decarburization system is relatively simple, which is suitable for small sample prediction. In order to study the factors affecting the stability of decarburization device, verify whether the adjusting method and parameters of production in the current working conditions meeting the production requirement, and make the decarburization effect to be the best. Combined with the operating parameters of decarburization device in LNG plant during three phases of start up-production, stable yield and fall-production of shutdown, the grey system GM (1, N) model was selected to simulate the device. Simulation results directly reflected the operation rule of decarbonization system. The subjective factors of influencing decarburization effect were found. Results showed that the inner environment temperature (bottom and top) of absorber was the subjective factor influencing the decarburization reaction. The production running adjusting parameters of the device need to be checked and adjusted regularly to ensure the best decarburization effect.