Insulator leakage current can comprehensively reflect the insulator voltage level and contamination state

which takes effect throughout the entire development process of the insulator flashover

so extraction and selection of leakage current characteristics have a prominent influence on prediction of flashover. Based on artificial pollution test

fractal dimension feature quantity of composite insulators leakage current is derived by using fractal theory

the variation features of waveform and fractal dimension of leakage current in different sections is analyzed in the whole process of flashover development

and leakage current waveform fractal characteristics in three different level of contamination is compared.The results shows that in the process of flashover

fractal dimension of leakage current waveform descends on the whole;and there is a slight difference in the leakage current waveform fractal characteristics depending on different contamination level.Experimental analysis show that the leakage current waveform fractal dimension can directly reflect its waveform characteristics and provide effective early warning for insulator flashover.