Abstract: In view of the deficiency of the current calculation model of equivalent icing thickness of suspension tower ground wire under uneven icing, this paper improves the calculation model of equivalent icing thickness of suspension tower in South China, and proposes a calculation model of equivalent icing thickness of suspension tower ground wire considering the deflection of suspension string. The influences of uneven icing on the deflection of suspension string under four working conditions, such as, high elevation discrepancy span and large span, high elevation discrepancy span, large span non high elevation discrepancy span and non large span, are studied by finite element simulation. In order to verify the applicability of the improved model, the errors of the calculated results of equivalent icing thickness before and after the model are compared with the theoretical value of the average equivalent icing thickness. The results show that the equivalent icing thickness calculation model before improvement is suitable under four conditions when the average equivalent icing thickness is less than 10 mm. When the average equivalent icing thickness is more than 10 mm, the relative errors of the calculation model of the equivalent icing thickness before improvement under four conditions are 47.14%, 50.70%, 73.33%, and 99.41%, respectively. The relative error of the improved model after considering the deflection angle of the suspension string is reduced to 6.42%, 6.13%, 9.27% and 13.39%. The improved model can greatly reduce the error of the calculation results.