One-dimensional organic structures with well-oriented -aggregation, strong emission, and ease of processability are desirable for optoelectronic waveguiding devices. Herein, a strategy is developed to attain this objective by self-assembling platinum(II) acetylides into fluorescent supramolecular polymers via cooperative mechanism. The resulting high-molecular-weight supramolecular polymers are capable of forming electrospun microfibers with uniform geometry and smooth surface, which enable light propagation with extremely low scattering loss (0.008dBm(-1)). With the elaborate combination of bottom-up supramolecular polymerization and top-down electrospinning techniques, this work offers a novel and versatile avenue toward high-performance optical waveguiding materials.