Fabrication of cross-linked 1,10-diaminodecane-poly methyl methacrylate/carbon nanotubes/graphene nanocomposites PMMA/CNTs/GNP(a-c) has been executed effectively by multistep chemical cross-linking reaction. The environmental response of the fabricated material has been investigated in intensive studies. The synthesized hybrid nanocomposite effectively removed crystal violet (CV) and methyl blue (MB) from the simulated textile wastewater solution. The comprehensive delineation of the prepared nanocomposite was examined using SEM, X-Ray Diffraction (XRD), and FTIR analysis. The outcomes revealed that adsorption capacity was influenced by six variables (e.g., contact duration, starting concentration, adsorbent mass, the effect of the solution pH, temperature, and the impact of KNO3). Additionally, studies on thermodynamics and regeneration have been published. The elimination process involves chemical adsorption based on theories of pseudo-second-order kinetics. The pseudo-second-order model predicted that the maximal adsorption capacities of the MB and CV dyes would be 20.83 and 22.42 mg g−1, respectively, best fitting the experimental results. This work is a pilot case study highlighting the outstanding potential of PMMA/CNTs/GNP nanocomposites as materials for CV and MB dye elimination.