In recent years, the scanning SISO(single-input-single-output) array near-field imaging technology has attracted widespread attention in civilian fields, such as security inspection and medical treatment. However, during the echo processing of traditional range migration algorithm, the multi-step approximation and interpolation operation cannot be avoided, and the adverse effect caused by signal propagation attenuation is ignored. Therefore, this research proposed a FFT (fast Fourier transform)-based scanning SISO array near-field imaging technology in which the amplitude attenuation factor in the echo model was preserved. The convolution operation on azimuth and altitude dimensions was performed according to the characteristics of the target echo equation. The target image could be obtained by applying FFT and coherent accumulation steps. Simulation analysis and experimental results show that the proposed method can not only improve the target image quality while ensuring the efficiency of image reconstruction, but also effectively reduce the impact of signal spatial propagation loss on the imaging quality.