Provided are an apparatus and method for minimizing a distribution loss which reconstructs the system construction of a distribution system in consideration of section load characteristics of mutually different distribution system. The apparatus for minimizing a distribution loss which determines a loss calculation period for detecting a loss minimization time point using mutually different distribution systems, calculates loss values of mutually different distribution systems set according to each time point of the loss calculation period, and calculates a total loss value, and selects the mutually different distribution systems one by one during the loss calculation period, and calculates a loss value for specific systems of each distribution system in consideration of a change of a section load in each selected distribution system, determines a loss minimization time point using the specific system loss value of each distribution system and the total loss value.