This paper proposes a co-optimal strategy using line hardening

mobile devices (mobile ice-melting device

mobile emergency generator

mobile energy storage system)

and repair crew dispatching to improve distribution system resilience during ice storms. A multi-stage defender-attacker-defender model is established to take into account interactions and coupling relationships between different measures. In our proposed model

ice storms will attack the distribution and transportation system in a worst-case scenario

affecting system performance from various perspectives. Corresponding to the different operating states in the distribution system affected by ice storms

aiming at minimizing the weighted load shedding value

this paper applies various measures to different stages to improve the response and defense capabilities to ice storms and realize restoration of the distribution system ultimately. The nested column-and-constraint generation algorithm is used to solve the model efficiently. The effectiveness of the proposed model and solution method for enhancing the distribution system resilience is verified on the modified IEEE 33-bus distribution system and modified real-world zone of Caracas 141-bus distribution system.