Abstract: Combined with the present status of the research and application of glass fiber reinforced plastic （FRP） tower, taking Lingzhou-Shaoxing ±800 kV UHVDC transmission line engineering as research background, this paper put forward the force mechanism and designing scheme of FRP rotation cross arm, and carried out simulation analysis based on tower-line coupling model. The analysis results show that the rotation FRP cross arm turns freely under the longitudinal unbalanced tensions, so the longitudinal unbalanced tension can be released, the stress of FRP cross arm and tower can be reduced, and the weight of tower and the cubic amount of concrete foundation can be effectively reduced, which has good economic and social benefits.

Key words: glass fiber reinforced plastic （FRP）, rotation cross arm, FRP cross arm, tower-line coupling