Abstract: 1-bit technique has good noise immunity on synthetic aperture radar imaging. Most 1-bit reconstruction algorithms use L1 or L2 norm as sparse regularization. In this paper, a L1/2-norm that can obtain better sparse solutions is proposed, an alternating direction multiplier method is used to reconstruct the echo signal, and its performance is verified by simulation experiments and actual echo diagrams. Compared with the fixed threshold, the variable threshold can retain partial amplitude information of the target reflection coefficient. Thus an adaptive threshold is further used to approximate the echo data to the greatest extent. The simulation results show that, compared with the time-varying threshold algorithm, the error between the restored image and the original image is smaller, and a more obvious effect under the L1/2 norm is gotton. When the signal-to-noise ratio is low, the adaptive threshold also performs better than the time-varying threshold.