A distribution transformer rotation sequence automatic generation and evaluation method based on a directed graph comprises the following steps: (1) establishing a directed graph and a correlation matrix thereof according to the distribution transformer capacity transformation demand; (2) solving a rotation sequence based on the directed graph; (3) analyzing the distribution transformer purchase demand and remaining quantity through the directed graph and capacity-reducing path choosing; (4) analyzing the starting position and priority order of a route based on a loop and a non-loop; and (5) evaluating the rotation sequence according to the distribution transformer rotation principle and based on cost. According to the invention, through the directed graph and the adjacency matrix thereof built after capacity-based sorting, distribution transformer capacity change analysis is more intuitive, and analysis of the distribution transformer rotation sequence based on the connectivity of the directed graph is more operable. With the aid of the distribution transformer rotation sequence, the rotation priority order and the starting distribution transformer position can be well determined. Different distribution transformer rotation sequences are evaluated based on cost, and the cost of distribution transformer transformation can be better controlled. The method of the invention can provide technical support for the transformation of distribution transformers in distribution networks.