A simple and robust process has been developed to control the growth of the organic nanowires in situ self-assembled in a polymer matrix, lift off the nanostructure/polymer composite film from the mother substrate for storage and transfer, and remove the polymer host prior to usage. Every step was completed through a solution process, which ensured the process's simplicity and low cost. The realization of large-sized nanowire/polymer composite film demonstrated the necessary process scalability required by the industrial roll-to-roll manufacturing.