The invention relates to a fixed value standardization method and system for online checking and offline setting. According to a pre-established key fixed value standard library, fixed value items inan online checking system and an offline setting system are matched automatically to form unique standardized numbers of fixed value items of the online checking system and the offline setting system;and on the basis of the unique standardized numbers of fixed value items, closed-loop control of the online checking system and the offline setting system is carried out. The pre-established key fixed value standard library includes a unique identifier number rule of a fixed value item. Therefore, problems of tedious current fixed value docking work mode process, large workload, high error frequency, and low data updating frequency are solved. A basic data standardized guarantee and a technical support are provided.