The quantity of seismic signal data is very large. If merely composite succession FFT algorithm is used to process the seismic signal, the data quantity will be doubled and redoubled, and hence the calculation will become cumbersome. Aimed at the problem of the real succession of the seismic signal, this paper deals with the fast Fourier transform of the real signal. Three fast Fourier transform algorithms for real successions are put forward, a quantitative analysis for reducing the calculation work was made, and the practical seismic data were computed. It can be seen from the analytical and computation results that these three methods can obviously reduce the quantity of calculation and save the storage space of the computer.