The invention relates to a 
zinc oxide lightning arrester state on-line detection method, which is suitable for the power 
system lightning arrester on-line detection technology field. The 
zinc oxide lightning arrester state on-line detection method comprises steps that databases are respectively established, and in an initial state of a 
lightning arrester, resistances under conditions of different 
voltage levels, temperatures and 
humidity and resistive current components generated by 
interphase interferences under the condition of different 
voltage levels are stored and updated; the leakage 
total current of the 
lightning arrester and the 
voltage of the line of the 
lightning arrester are detected, and then resistive leakage current without the 
interphase interferences is acquired, and a voltage and resistive leakage current fundamental wave component is acquired by adopting 
fast Fourier transform, and therefore the resistance of the lightning arrester is acquired. The resistance is searched in the databases according to the temperature and the 
humidity of the current operation environment of the lightning arrester, and is compared with the calculated resistance, and then the current state of the lightning arrester is acquired. The 
zinc oxide lightning arrester state on-line detection method is advantageous in that the influences of the interface interferences, 
harmonic waves, the temperatures, and the 
humidity on the parameters of the lightning arrester are effectively reduced, and the current operation state of the lightning arrester is acquired accurately, and the related parameters of the lightning arrester are detected and calculated automatically, and therefore power-
cut detection of maintainers is not required, and maintenance efficiency is greatly improved.