The phenomenon of shear-induced crystallization is commonly observed for crystalline polymers. Herein, we demonstrate that this concept can be applied to promote the self-assembly of the conductive nanowires (NWs) in dilute solution. It is found that, by a simple rotation-assisted method, higher yield of poly(3-butylthiophene) (P3BT) NWs in anisole solvent was obtained than the case under static condition. While the length as well as the crystal modification of the NWs is not changed. The structural analysis suggests that the P3BT NWs take the crystal modification of form I rather than the conventional form I, independent of the sampling condition. This conclusion is further confirmed by investigating the phase transition behavior of the NWs using synchrotron radiation wide-angle X-ray diffraction technique. Unexpectedly, the active layer in field-effect transistor (FET) device fabricated by well-shaped pure NWs network formed under the rotation field shows the comparable carrier mobility with that fabricated by the ambiguous NWs network obtained under the static condition, which implies that the amorphous part plays an important role in affecting the electrical property. (c) 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 1027-1034