A calculation method based on fast Fourier transformation and micromagnetism (FFTM) is presented.It is applied to the numerical calculation of two-dimensional nanomagnetic systems.Numerical calculations show that the results of FFTM method are similar to those of the method in which the dipole-dipole interaction is performed straightforward with truncation.The precision and the speed of calculation are improved.It is shown that the FFTM method provides a fast and efficient way for magnetic systems with long-range dipole-dipole interaction.