The impact of the air flow spoiler on the aerodynamic characteristics of iced transmission lines and its effects of anti—galloping were researched.The aerodynamic characteristics curves of the crescent iced transmis. sion line were simulated by the method of Computational Fluid Dynanlics(CFD).The average aerodynamic charac. teristics curves of eight equal sections in a circular pitch of the crescent iced transmission line installed with the air spoiler were simulated.The results show that the drag coefficient of the crescent iced transmission line installed with air flow spoiler is larger than the crescent iced transmission line.The lift coefficient curve doesn't change much.The absolute value of negative slope of torsion coefficient curve decreases.The air flow spoiler is useful for preventing galloping.