In view of the lack of effective dynamic evaluation schemes for current low-voltage reconstruction projects of distribution networks, starting from the economics and governance effects of project reconstruction, and taking into account the dynamic growth of loads, on the basis of the station-feeder-transformer-user(S-F-T-U) low-voltage refined evaluation system, the comprehensive voltage qualification rate, load-voltage sensitivity, effect cost ratio and other indicators are proposed to dynamically evaluate the distribution network reconstruction project. The comprehensive voltage qualification rate is used to characterize the level of voltage quality in the area, and measures the effect of low voltage treatment before and after the project reconstruction. The load-voltage sensitivity characterizes the impact of load changes on voltage quality in the region, establishes the relationship between regional voltage deviation and load, and estimates the voltage quality after the project transformation. The effect-cost ratio is used as a dynamic evaluation index for project transformation. The effectiveness of the method has been verified through an example, which provides a theoretical basis for the evaluation of low-voltage transformation project of distribution network.