The radiation signal was sampled by using the point corona discharge simulation system

and the characteristics of the signal in time-domain and frequency-domain were analyzed to analyse the corona discharge characte ristic of radiation signal better.The results indicate that the direction of the first pulse of the radiation signal is opposite under different polarities of the discharge voltage.With different polarities of the discharge voltage

the characteristics of the radiation signal in time-domain are different

but in frequency-domain the distributions of the frequency spectrum are basically identical.The energy of the discharge signal concentrates mainly on 50～100 MHz

and the range of radiation frequency is below 150 MHz.