Aerodynamic coefficients of bundle conductor lines in ice zones are the foundation to investigate the dynamic responses of transmission lines, such as galloping, ice-shedding and so on. In this paper, numerical flow field model for aerodynamic characteristics of UHV six-bundle transmission lines is carried out, and its validation is verified by compared with wind tunnel test data. Based on the model, the aerodynamic characteristics of six bundle conductors under different ice types, including crescent ice, D-shaped ice and fan-typed ice, are investigated. It is obtained that the aerodynamic coefficients are highly affected by the ice type of conductor and the attack angle. The aerodynamic coefficients of leeward conductors are considerably affected by the windward conductors.