Abstract: In view of problems of traditional current detection method which took electromagnetic current transformer as the core that it was difficult to install and maintain, took up a lot of space and has low precision, a current detection system of underground intelligent substation with Rogowski coil as sensing head was designed. Design of integral reduction circuit and adaptive amplifier circuit was introduced, and the system stability analysis as well as Rogowski coil test, linearity test, frequency characteristic test and temperature characteristic test were carried out. Test results show that the system has high precision and good linearity.