In order to highlight target in multispectral remote sensing and overcome the human error caused by threshold, a new method is proposed here. Image of target similarity is firstly calculated by spectral energy level matching (SEM) algorithm and as a band added to original image; Then, band normalization is performed on the new image to reduce the effects caused by the order of magnitude in different bands; Finally, a false color image that highlights the target is made by RGB composed of the first three bands (3, 2, 1) in MNF transformation. Results from the experiment of highlighting the main rock-type tuffaceous siltstone in Hatu area, Xinjiang province, China show that (1) the new method can highlight target for the increment of target’s information and weights during the process of transformation by adding a band representing target’s similarity to the original image. Therefore, it overcomes the shortcomings existing in the common transformations on space information-although different objects corresponding to special information space are distinguished, targets the authors wanted can not be highlighted yet; (2) The new method can distinguish more objects than original maximum noise fraction (MNF) transformation because it unifies the tone for the same object’s type by suppressing none target information using SEM method; (3) In addition to highlighting tuffaceous siltstone in the study area, the new method can be used widely in other fields such as soil, concrete, altered mineral etc.