The invention provides a bay decoupling method for an SCD (Substation Configuration Description) model of an intelligent substation. The method comprises the following steps of (1) performing bay modeling of the SCD model; (2) analyzing a bay association relationship; (3) performing bay physical decoupling; (4) analyzing associated bay configuration modification content; and (5) combining bay files. According to the method, a means of isolating change influence ranges of different business configuration information is provided, so that the complexity of SCD file application is lowered.