In the present work, laser-induced directed dewetting of smooth SiGe thin films generates SiGe islands with high aspect ratio of 0.9 on the surface. The laser-induced island is fully relaxed, and the thermal effect accelerates the relaxation of strain, which finally forms disorder surface islands. Furthermore, it is interesting to note that these surface SiGe islands can be served as masks, and uniformly orientated degree (30°) Si-based nanowires can be fabricated by Ar IBE. The proposed laser programming method features high precision, tunability and scalability with relatively limited patterning effort and opens a new way for fabricating efficiency light-emitting Si-based nano-Ge/SiGe heterostructures and Si integrated-circuit technology.