A group of free-standing 3560ZGu2 transmission towers of 60 kV lines was taken for the calculation. The finite element software SAP2000 was first used to analyse icing transmission towers of different heights
the critical cladding ice thickness of buckling transmission towers and the critical wind speed of buckling icing transmission towers were calculated
and the influence of maximum vertical distance and the ground type was quantitatively also analyzed. The research shows that the wind load is the chief reason for the instability and failure of transmission towers,and that with the increase of calling heights,the buckling critical wind speed of icing transmission tower decreases while the ice thickness of buckling transmission towers is not in proportion with the increase.