Abstract: This paper proposes an energy-saving and loss reduction technology based on the coordination of low loss transformer selection and load optimization to address the common problem of high losses in 10 kV distribution network transformers. Firstly, establish a life cycle costing optimization model, introduce measured load curves to calculate the equivalent hours of annual maximum load loss, and use the net present value method to achieve quantitative selection decisions for low loss transformers. Secondly, a genetic algorithm (GA) is used to construct a load optimization model, with the goal of minimizing the total loss throughout the day, to achieve global optimization of the capacity configuration and operation mode of multiple transformers. The verification results of a 10 kV distribution system in a commercial complex show that amorphous alloy iron core transformers reduce no-load losses by 68.18%, and the GA load optimization strategy further reduces comprehensive losses by 17.64%. After collaborative application, the annual electricity cost savings are 10710.24 yuan. This article provides a systematic solution from equipment selection to operation optimization for energy-saving and loss reduction of distribution network transformers, which has important application value in promoting loss reduction and efficiency improvement of distribution networks.