Magnetic fabric is a sensitive strain indicator. Under the function of single stress, the direction of magnetic lineation is consistent with the bedding strike at the early stage of layer parallel shortening. However, in the low deformed sedimentary region under tectonic superposition, another different directed stress would rotate the arranged magnetic minerals, which will induce that magnetic lineation is oblique to the bedding strike. The Northwest Sichuan Basin is a typical tectonic superposition region in Cenozoic, where the deformations transferred from the Longmenshan and Micangshan affected together. Investigation of magnetic fabric was carried out in the Northwest Sichuan Basin, 172 samples were drilled in 18 sites in 3 crosssections. Three low deformed magnetic fabrics were observed in the study area: sedimentary magnetic fabric, initial deformation magnetic fabric and pencil structure magnetic fabric. Because of deformation superposition, deformation intensity from basin to orogen is not increasing, and the magnetic lineations are not in the same direction. From basin to orogen, the deformation transferred from Micangshan becomes more intensive, the magnetic lineation fits bedding strike at the interior of basin, and magnetic lineation is oblique to the bedding strike in the region adjacent to the orogen.