With the construction of the novelpower system, a large proportion of renewable energy is being integrated into the distribution network, changing the internalpower flow of the distribution network, resulting in frequent power switching occurring between the transmission and distribution networks. To address the issue of transformer life degradation exacerbated by forward or reverse power transmission overload, this paper proposes a coordinated control strategy for various types of controllable resources in the distribution network to optimize transformer life under frequent current switching. Atransformer life calculation model is introduced, clarifying the strong positive correlation between transformer load rate and insulation life. The internal changes of the transformer under frequent current switching are considered, and a coordinated control measure for controllable resources in the distribution network including a constraint on the upper threshold of transformer load rate is constructed and a corresponding solution strategy is proposed. This measure effectively improves the operating conditions of the transformer while ensuring the safety and economy of the distribution network voltage. Simulation analysis on the improved IEEE 33-system shows that the proposed method can effectively reduce the maximum load rate of the transformer under various scenarios, providing scientific guidance for optimizing transformer life.