A space-time load prediction method based on a graph neural network and regional gridding relates to the technical field of power 
system power distribution network planning, and comprises the following steps: step 1, 
feature engineering: selecting data features; 2, constructing a 
network topology, and fusing the feature information in the step 1; 3, transmitting the feature information of each 
power supply unit based on the 
topological graph in the step 2; 4, predicting the load of the 
power supply unit based on the network 
topological graph obtained in the step 2 and the 
power supply unit information obtained in the step 3; and step 5, based on the previous steps, dividing grids, and carrying out 
unit load power supply grid load prediction. According to the method, a to-be-predicted region is divided into a plurality of grids, and a neural network load prediction model is used for a load structure to obtain load prediction results of the whole city at different time and regions; a load prediction model is established through a gridding technology, a graph neural network, regression prediction and other methods, 
power grid topological structure information is fused, and more accurate prediction is provided for a power distribution network planning load prediction task of a power 
system.