A kind of infrared image enhancing method based on discrete stationary wavelet transform is given. After making discrete stationary wavelet transform to an infrared image ,enhancement is done by a kind of nonlinear enhancing operator in the high frequency subbands of each decomposition level respectively. According to the result of experiment ,the given algorithm can enhance the contrast of the target in infrared image effectively while it also extrudes the detail information of the target in infrared image well. In performance ,the algorithm is better than traditional histogram equalization method , un-sharp mask method and enhancing method based on discrete orthogonal wavelet transform.