In order to study AC line corona characteristics and electromagnetic environment of ultra-high voltage（UHV） transmission lines

it is necessary to obtain the corona characteristic parameters of different types of multi-split wire.The authors introduced the test methods and principles of corona effects based on ultra-high-voltage cage

analyzed and processed the relative data to get wire’s audible noise power density and radio interference excitation function

and compared the data with the existing foreign from corona characteristics empirical formula to prove the validity of the test data.Moreover

the AC corona characteristics were analyzed with different influencing factors such as different weather

different sub-wire radius

different spacing distance

etc.to ensure the economy

energy saving

and environmental protection for ultra-high voltage transmission engineering.