We have demonstrated that our continuous flow microfluidic devices operating under 3D control of the RD zone can enable the direct and continuous fabrication of SCO polymeric fibers with a homogeneous distribution of SCO material within the polymer matrix. The resulting SCO composite fibers exhibit both magnetic bistability and thermochromic properties upon heating and cooling. By leveraging the precise control over the RD zone offered by the microfluidic chip designthrough adjustment of precursor injection positions and flow rateswe can tailor SCO composite fibers with hollow or solid structures that display a variety of magnetic behaviors. Moreover, this technique also facilitates the printing of freestanding architectures with defined shapes and the isolation of fibers as self-standing units. Building on these capabilities, we engineered a new chip design that provides precise encoding of SCO composite fibers by leveraging spatiotemporal control over the distribution of the SCO material within them, thereby significantly expanding their practical applicability. Our findings highlight the transformative potential of this microfluidic approach, opening novel pathways for scientific and industrial communities to incorporate molecular switches into materials suited for real-world applications.