The invention discloses a co-prime array DOA (Direction-of-Arrival) estimation method based on angle-space frequency domain fast Fourier transform, and aims to solve the problems that an existing method is high in calculating complexity; the method comprises the following steps: enabling a reception end to construct a co-prime array; using the co-prime array to receive incident signals, and modeling; deriving second order equivalence virtual signals corresponding to an augmented virtual uniform linear array according to co-prime array received signals; defining an angle-space frequency and using same to describe the second order equivalence virtual signals of the virtual uniform linear array; pre-windowing the second order equivalence virtual signals described by the angle-space frequency;zero filling the pre-windowed second order equivalence virtual signals; carrying out fast Fourier transform operation for the zero filled second order equivalence virtual signals, and building a spatial spectrum; carrying out DOA estimation according to the built spatial spectrum. The method can improve the DOA estimation degree of freedom performance while reducing the calculating complexity, and can be easily realized on real systems.