Abstract: The system configuration description（SCD） describes the key information of the secondary system of the intelligent substation, such as the virtual terminal correlation and virtual circuit connection, the correctness of the secondary virtual circuit is very important to the safe and reliable operation of the secondary system of the whole station. The validity of its correctness at present depends on manual inspection according to its professional knowledge, which is very inefficient and inaccurate. Therefore, this paper analyzes the secondary virtual circuit structure of intelligent substation, and then studies the attributes of intelligent devices in SCD file and their correlation, including region division, data flow direction, port information matching, etc.,a secondary virtual loop validation method based on region partition and data flow direction and port information for intelligent substation is proposed, and the software and hardware for SCD file secondary virtual loop validation are developed based on the proposed secondary virtual loop validation method, the test results show that this method can quickly, reliably and accurately complete the secondary virtual loop test of SCD file.