Abstract: The received information of image sonar in azimuth can be regarded as the convolution result of scattering information with beam pattern, so the scattering information can be recovered by deconvolution. However, there is inherent ill-conditioned trouble in the solution of inverse problem. To solve the problem, the maximum entropy is introduced in this paper to use as the regularization constraint term, which is not limited to the distribution model of the targets, and the Frieden entropy is used to evaluate the final solution. Meanwhile, the image entropy is used to compare the results obtained by different algorithms. The results show that this algorithm has the good performance even in the low signal to noise ratio (SNR) compared with the constrained iterative deconvolution.