Distributed energy sources as well as a high percentage of uncontrolled access to a large number of dynamic loads (electric vehicles, etc.) will lead to frequent two-way dramatic fluctuations in the power flow of the distribution transformer, which in turn will affect transformer life expectancy. In this paper, we propose to effectively improve the life expectancy of transformers by optimizing the distribution of active and reactive currents in the distribution network through the synergistic effect of lead-acid battery storage systems and reactive power compensators. Firstly, the distribution transformer life loss model based on hot spot temperature, the energy storage system model and the reactive power compensator model are established. Then, in order to minimize the maximum loading rate of the distribution transformer, a nonlinear model is established with the purpose of minimizing the variance of the load curve within one day of the optimization cycle of the distribution network. The nonlinear model is then reformulated into a linear model through the method of second-order conic planning, and finally, the commercial solver is employed to solve the problem. Finally, it is tested in the distribution system of IEEE33 node. The results of the simulation demonstrate that the peak shaving and valley filling of the load curve by the energy storage system and reactive power compensator can effectively address the imbalance between energy supplies and demands over time. This approach reduces the maximum load ratio of the distribution transformer at peak loads, which in turn mitigates the risk of hot spot temperatures in the distribution transformer’s windings at peak loads. Furthermore, it minimizes the loss of distribution transformer life during operation, thereby extending the expected lifespan of the transformer.