基于线长恒定的原理，预置了跳线软体部分的弧垂，建立了硬跳线系统的状态方程。根据斜抛物线理论和三维空间技术，提出了跳线三维轨迹和电气距离的计算方法，工程计算实例验证了该解决方案的可行性和可靠性。

Based on the principle of constant length, the state equation of hard jumper system was derived by presetting the sag of the hard jumper’s soft part. Subsequently, according to the inclined parabola theory and 3D space technique, the calculation methods of 3D trajectory and electrical distance of the jumper were put forward, of which the feasibility and reliability were verified by an engineering example.