This study comprehensively investigates the potential of reed straw waste (RSW) for thermochemical conversion into bioenergy and value-added chemicals. The physicochemical property characterization confirmed the potential of RSW as both a renewable fuel and a source of chemical compounds. The high heating value (17.16 ± 0.20 MJ/kg), average activation energy (253.10–297.04 kJ mol−1), Gibbs free energy (153.45–158.39 kJ mol−1), and enthalpy change (248.10–292.04 kJ mol−1), underscored the significant potential of RSW for bioenergy production through pyrolysis and its compatibility for co-pyrolysis with other waste materials. Pyrolysis product analysis revealed that syngas constituted 42.25–66.48 % of the total three-phase products, with combustible components like H2, CO, and CH4 comprising 84.14–89.77 % of syngas. Bio-oil represented 18.94–35.23 % of the total three-phase products, primarily composed of phenols (30.88–46.04 %), acids (1.12–16.05 %), furans (8.84–14.46 %), ketones (9.34–16.33 %), alcohols (4.59–13.68 %), and aldehydes (5.54–11.10 %). BET and FTIR analysis of the biochar indicated that RSW biochar possessed a well-defined porous structure and abundant surface functional groups, making it capable of achieving a maximum adsorption capacity of 185.35 mg g−1 for the malachite green (MG) dye in the aquatic environment. In summary, this study holds significant implications for mitigating environmental pollution resulting from improper disposal of RSW and promoting its high-value utilization.