Abstract: Currently corona discharge detection can be achieved by measuring its electromagnetic radiation field in a wide-band. However, the wide-band test brings in more electromagnetic interference, resulting in a low signal to noise ratio(SNR), and limits the detection distance. Hence, the narrow-band testing method for remote detection of corona discharge is proposed. The principle is to select a suitable narrow-band frequency with a high SNR to test the radiation field by analyzing corona energy distribution and the background electromagnetic interference. A test experiment is carried out and its result is analyzed. Comparing with wide-band test, the narrow-band test has remoter detection distance for higher SNR and anti-interference ability. The frequency band from 120 MHz to 315 MHz in which has few interference and high SNR of more than 4 dB, is suitable for remote detection for corona discharge. The proposed narrow-band-test method, by which the detection distance becomes further after signal processing, is general and has a great significance for developing the current remote detecting technologies of corona discharge.