This article proposes an investment allocation method for hierarchical classification of distribution network investment under the new situation. Firstly, the total investment amount is determined based on the unit investment effect of the overall planning of the distribution network in historical years. Then determine the allocation ratio for different projects based on the type of project. Further allocate the overall investment amount to each grid within the limits of the power supply grid. The accuracy and effectiveness of the proposed method were verified through case analysis. The proposed method not only achieves investment allocation in the distribution network, but also determines the total investment amount. It has certain engineering practical significance.