Abstract：Up to now，the distribution network planning project optimization method rarely considered the

impact of the speed of load growth on the power supply efficiency of the project and the year when the project is

selected，and rarely considered the urgency，technical benefit and economic benefit of the project at the same time.Therefore，the optimal model for medium and low voltage distribution network planning projects was established with the goal of maximizing technical and economic benefits. According to the urgency of the project，the technical benefits of the project were rewarded and punished. In order to measure the annual change rate of the power supply benefits of the project，the differential weight method was used to obtain the five-year comprehensive level of power supply benefits after the project was put into operation. An improved multi-objective particle swarm algorithm solution model was proposed，and a series of project combination schemes with mutually advantageous objectives were obtained，and the optimal project combination scheme was obtained by multi-level screening of the project combination scheme set according to the target preference of the power supply enterprise. Taking the distribution network planning project database in a certain region as an example，it show that the proposed model can better consider the change of power supply efficiency and the urgency of the project，and achieve multi-regional and multi-objective comprehensive improvement.

      Key words：distribution network planning；project selection；reward the good and punish the bad；differential

weight method；multi-objective particle swarm optimization