<p>With the continuous advancement of society, water pollution has increasingly emerged as one of the most pressing issues in China. Constructed wetlands (CWs) are green and environmentally friendly process that have been widely applied in various types of wastewater treatment. Among various factors, the substrate plays a significant role in the treatment efficiency of CWs. The increasing production and disposal of solid waste, including municipal solid waste and industrial residues, contribute to environmental pollution and land resource depletion. The appropriate treatment of converting solid waste into substrate offers a viable solution for solid waste management while fulfilling the dual functions of ecological restoration in CWs and water quality improvement. In this study, a systematic review of various types of substrates utilized in CWs has been conducted, the potential application of solid waste as a substrate has been explored, and the methods for transforming solid waste into substrates have been investigated. Furthermore, this study proposes optimization strategies for the future development of solid waste substrates, aiming to provide a theoretical foundation and practical guidance for research in this field.</p>