Pseduo-color enhancement method of sub-band images of mid-wave infrared was presented based on both lαβ color space transform and wavelet packet transform. The color and luminance information of pseudo-color image obtained by RGB color mapping were separated by using lαβ color space transform. And the luminance part was replaced by the image fused from two sub-band images by wavelet packet transform, then pseudo-color enhancive image was obtained after inverse lαβ color space transform. The experimental results show that the local standard deviation and local entropy of enhancive image are increased by comparing with simple color mapping image, and the image enhancing has good perceptive effect.