Fine monitoring method and system for unsteady-state production link of additive

The invention discloses a fine monitoring method and system for an unsteady-state production link of an additive. The fine monitoring method and system are used for fine monitoring of two reactants obtained by two preparation raw materials in the additive in the unsteady-state production link respectively. Parameters obtained at a plurality of sampling points by a sensor in reaction equipment are used as variables, a controller sets an initial moment and a relaxation factor, the initial moment is iteratively optimized based on a reaction threshold value, the relaxation factor is iteratively optimized through the number of clustering centers, and an unsteady state production link is divided into a stable reaction period and a transition reaction period according to a clustering algorithm. When the first reaction data set of the stable reaction period and the first reaction data set of the transition reaction period are both smaller than the reaction threshold value, it is judged that the unsteady-state product