The invention provides a spatio-temporal correlation day-ahead plan load flow analysis method with uncertainty being taken into consideration. The spatio-temporal correlation day-ahead plan load flow analysis method comprises the following steps: obtaining next-day forecast wind speed of wind power plants in 96 time period within 24 hours; obtaining next-day output of the wind power plants; obtaining forecast error distribution of the next-day output of the wind power plants; carrying out independence conversion on random variables having spatio-temporal correlation; calculating semi-invariant of a load flow in each line; and determining relevant information for dispatching. The method carries out engineering algorithm processing on the forecast error distribution having correlation, thereby solving the problem that probability distribution having correlation cannot be obtained by utilizing a series expansion method directly. Analysis is carried out on the next-day load flow of each line in each time period through a Gram-Charlier series expansion method ; through such analysis method, probabilistic load flow problem can be solved conveniently and effectively; the method has a practical value; and the present series expansion method commonly used in medium/ long-term probabilistic load flow analysis is expanded to short-term plan load flow analysis, thereby providing more data support for economic dispatching.