Aiming at the problems of ultra-long points FFT implementation and computational efficiency encountered during the migration of DSP platform algorithms, this article combines TI's TMS320C6678 DSP, we use the FFT decomposition algorithm and the efficient memory access efficiency of the L2 memory segment to design a parallel processing method for ultra-long points FFT calculation by paralleling the EDMA movement of the DSP memory data and the FFT decomposition calculation.The specific implementation process of the method is described by 262144-points FFT calculation, and the calculation result of DSP is compared with the result of MATLAB, and the calculation error of the method is 10^-4.Finally, on the DSP platform, when the number of FFT points is the same, the calculation time of directly calling the FFT library function is compared with the calculation time using this method, which shows that it has better calculation performance in the ultra-long points FFT calculation.