In the airspace, Histogram Enhanced image is prone to cause grayscale faults, which will lead to excessive enhancement of image contrast, partial overlighting and unclear details. A new method of image enhancement based on human visual fitness function is proposed. First of all, the algorithm performs single layer transform on the image through the lifting wavelet. Secondly, it is balanced, interpolated and re-balanced in the low frequency coefficients of wavelet. Finally, the new low frequency coefficients are reconstructed and normalized, and the image is output through the human eye vision fitting function. The experimental results show that this method can effectively solve the problems that the enhanced image brightness is too high, the details are not clear or lost, and the gray level is not strong. The image enhanced by this algorithm has a soft visual effect and is more suitable for image subsequent processing and analysis.