A method for joint estimation of DOA and coupling matrix based on linear prediction is proposed for low resolution of mutual coupling calibration method in the case of small spacing antenna array. This method augments array aperture virtually according to linear prediction principle and calculates the coupling matrix by this virtual array. Then, this coupling matrix is used as the initialization matrix of joint estimation algorithm for coupling calibration. Simulation results confirm the effectiveness of the proposed method and provide the theoretical foundation for engineering realization. This method could also be applied in the field of tactical anti-jamming communication.