The invention discloses a power grid demand side dispatchable capacity prediction method and belongs to the technical field of intelligent power grid and computer data mining intercrossing. According to the method, basic user information, user interruption capability and user interruption wishes influencing the demand side dispatchable capacity are fully considered, further the most important influence factor is selected from the basic user information, the user interruption capability and the user interruption wishes, the selected influence factor is quantized in a grading mode, and a demand side dispatchable capacity prediction model is constructed in combination with a neural network. The invention further discloses a power dispatching method adopting the prediction method. Compared to the prior art, the method has higher prediction precision and accuracy, and can provide powerful data support for applications of power grid dispatching, electricity price setting, power grid reliability analysis and the like.