Textile and other industrial dyes as the most prominent organic compounds that pose variety of health risks require efficient treatments before discharging into the environment. In this work, a novel polymeric network has been synthesized via cationic ring opening copolymerization of glycerol and elemental sulfur and used as an adsorbent for cationic dyes. The structure and composition of the synthesized compound was investigated using different spectroscopy methods as well as elemental and thermal analysis. Structural analyses were performed on this polymer to identify the structure. FT-IR spectrum showed the presence of sulfide, ether, and hydroxyl bonds in the structure. SEM images showed a sponge-like and porous morphology for the polymer. XRD analysis proved the amorphous structure with a broad peak in the 2ϴ= 10° - 35° region. TGA analysis also showed that this polymer has good thermal resistance. EDX analysis confirmed the presence of sulfur, carbon, and oxygen atoms. BET analysis showed that the pore size in this polymer is about 1 nm to 22 nm with an average size of 4.6 nm and a surface area of 88.7 m2/g. Solid-state NMR spectrum confirmed the presence of C-S bonds in the polymer structure. The obtained polymeric network with 6 µm average pore size showed a high potential to remove industrial dyes form contaminated water. Different parameters including initial dye concentration, time, pH, quantity and size of adsorbent as well as temperature were investigated to gain information regarding the mechanism of dye adsorption. Our data demonstrated a high ability for this compound to remove Janus Green (JG) and Crystal Violet (CV) from water selectively. The maximum adsorption capacity of this compound for JG and CV were 267 mg g-1 and 226 mg g-1 respectively and didn’t change after several recycling. Given the simplicity of the synthesis and the unique physicochemical properties such as high adsorption capacity, the synthesized polymeric network is a promising candidate for dye removal and water treatment.