Multispectral false color composite（FCC） images are widely used in interpretation of linear structures

which are directional because of the restriction of tectonic stress field.However

when the satellite image illumination cannot match the directions of linear structures

the structural features are less visible and their interpretations cannot be clearly recognized.Therefore

the paper brings out a new technique based on directional illumination simulating from digital elevation models（DEMs） to enhance multispectral images

which can enhance the structure lineaments by exchanging the traditional illumination model to the optimum illumination perpendicular to the targets

and allow the interpretation of the directional structure lineaments by using certain direction illumination.The paper interprets the fault-related lineaments by remote sensing image in southern segment of Longmen Mountains thrust belt

and the accurate identification of faults is the key to understanding tectonic structure for future work in oil and gas exploration.