In order to solve the problems of low testing efficiency and safety of the two circuits of the intelligent substation, "non-intrusive is introduced. Based on IEC 61850 second edition standard and automatic test technology, non-invasive automatic test system is developed. Firstly, this paper analyzes the secondary circuit testing principle and objective, then describes the key technology of "non-intrusive" system. Finally, combined with the actual operation, it proposes the introduction of a "non-intrusive" concept of security scheme and testing process. Through non-intrusive type automatic test system of intelligent substation secondary circuit testing, the realization of the project site does not change the station device configuration and physical link, namely, the completion of the testing work of secondary circuit significantly improves the engineering test work efficiency and intelligent substation operation safety.