The invention provides an electromagnetic compatibility forecasting method based on a function link neural network. The method comprises the following steps of: (1) taking n times of signal radiation strength statistical data as an initial input' (2) expanding one-dimensional data of the initial input to be two-dimensional data to obtain an input m of a two-dimensional function link neural network; (3) calculating a weight value of the function link neural network to obtain a forecasting function f(y'); and (4) according to the forecasting function, forecasting the electromagnetic compatibility between electrical elements. By the electromagnetic compatibility forecasting method based on the function link neural network, the dimension of the input part is expanded, and the conventional nonlinear problem is converted into a linear problem, so that the shortcomings of the conventional gradient search algorithm can be well overcome; and the problems of relatively complicated and troublesome multi-layer calculation of the BP neural network are solved.