Abstract: This paper proposes an adaptive optimization method. The model structure is selected through mechanism analysis and model structure identification. The dynamic model parameters are identified on-line using the process data, then the gradients of the object function for every operating variable are computed based on the model identified. Finally the optimal direction to move the working point is decided. The software ANOPT designed based on the algorithm has been applied to an industrial acrylonitrile apparatus and the result shows that this method has good adaptability, high anti-interference and quick optimization speed. As the method doesn't need any on-line component analyzer, it is suitable for actual industrial process.