Abstract: When passing through the frozen areas, the compact transmission lines are prone to the discharge tripping and fittings damage accidents due to the wires' detachment and jumping. Revealing the dynamic response law of the compact transmission lines after ice-shedding has an important guiding significance for the anti-icing designing and the reinforcement renovation of the line engineering. Taking the ice-shedding tripping fault of a 500kV compact transmission line as an example, numerical simulation was conducted to investigate the changes of the phase-to-phase gaps and the forces of the phase-to-phase spacers after ice-shedding of different phase conductors under the actual icing thickness; Subsequently, through parameter analysis, an optimization strategy for the arrangement of the phase-to-phase spacers on the line is proposed. The research results indicate: 1) Although setting phase-to-phase spacers can effectively suppress the vertical jumping height of the ice-shedding phase conductor and increase the gaps between the conductor and the ground wires, for the compact transmission lines with inverted triangle distribution, arranging phase-to-phase spacers will reduce the phase-to-phase gaps after ice-shedding. 2) Ice-shedding of the lower-phase conductor is more likely to lead to insufficient phase-to-phase clearance than ice-shedding of the upper-phase conductor; Moreover, when jumping up, the lateral pushing effect of the phase-to-phase spacer between the upper and lower phases on the lower-phase conductor may cause the insufficient gaps between the upper and lower phases on the non-connected side near the position of phase-to-phase spacer. 3) The number and arrangement positions of the phase-to-phase spacers on the compact transmission lines both have an impact on the phase-to-phase gaps after ice-shedding. Placing the phase-to-phase spacers away from the center of the span can effectively increase the phase-to-phase gaps. 4) The tension of phase-to-phase spacers between the upper and lower phases connected to the ice-shedding phase is the highest in both the upper and lower phases ice-shedding; The tension of the phase-to-phase spacers after the lower phase ice-shedding is greater than that of the phase-to-phase spacers after the upper phase ice-shedding, which may easily cause damages to the power fittings, and special attention should be paid to in the design. 5) Due to the tension effect of the adjacent spans on the ice-shedding span, the jumping height of the ice-shedding span may increase, thereby reducing the gaps between the phases. The use of tension strings instead of the V-shaped strings effectively reduces the negative impact of the adjacent spans.