Infrared images have the advantages of being employed in all weather conditions and exhibiting strong anti-interference abilities and are widely used in many fields. However, there are also problems of low contrast, high noise and blurred details, for which a high dynamic infrared image enhancement method based on wavelet transform is proposed. First, multi-resolution analysis is performed using wavelet transform, and the image is decomposed into a low-frequency information layer and high-frequency information layer, which are processed separately. The low-frequency information layer is subjected to contrast-constrained adaptive histogram equalisation to improve the contrast. The high-frequency information layer is enhanced with adaptive coefficients, and the gain coefficients are determined using gamma transform, which is designed to increase the applicability. Wavelet inverse transform is performed on the processed image to meet the desired requirements. It is shown that the algorithm can effectively enhance the high dynamic image contrast and improve the image detail information.