The treatment of river course pollution via photocatalysis has recently received significant attention. However, the problem of catalyst immobilization is hindering the popularization of powder catalysts in practical application. In this paper, graphitic carbon nitride (g-C3N4) was embedded on the surface of the sheath-core composite polyester fibers (LMPET) by a hot-melt adhesive process to construct a robust three-dimensional nonwoven catalytic platform (g-C3N4@LMPET). The results of field-emission scanning electron microscopy and digital microscopy showed that the scattered fibers were assembled in an irregular interpenetrating network system and the presence of the semi-coated inlaid g-C3N4 on LMPET structure was confirmed. This system showed a favorable photocatalytic activity towards the decomposition of antibiotics, such as sulfadiazine (SDZ) and sulfamerazine. Additionally, electron paramagnetic resonance spectra and ultra-performance liquid chromatography coupled with high-definition mass spectrometry analysis indicated that % O-2-is the predominant radical involved in the degradation of antibiotics in neutral solutions, avoiding the corrosion of polyester carriers during the pollutant elimination process. The superior performance of g-C3N4@ LMPET, in terms of tensile strength and regenerability, was confirmed through mechanical tests and cycling experiments. Furthermore, the consequence of SDZ photocatalytic degradation in different water media exhibited an intriguing practical application performance of g-C3N4@ LMPET. This work offers distinctive insight on the immobilization and largescale application of powder materials.