Abstract: In order to solve the problem that the composite cross arm tower is easy to bear large unbalance tension,an automatic adjustment device for unbalance tension of the tower is designed. Combined with the characteristics of the device,the calculation equations of unbalance tension are constructed,the iterative solution method is proposed,and the influence law of the structure parameters of the device on the adjustment effect of unbalance tension is analyzed. The results show that the unbalance tension adjusting device can effectively reduce the maximum unbalance tension at the hanging point under the condition of wire breaking or uneven icing.