The present study describes the fabrication of lignin-based drug microcapsules loaded with abscisic acid (ABA) through a self-assembly method, employing amine-modified sodium lignosulfonate (ASL) as the wall material and ABA as the core material (ABA@ASL). The ABA@ASL exhibits a regular spherical morphology with a drug loading efficiency of 37% and an encapsulation rate of 74%, demonstrating exceptional characteristics in terms of sustained drug release and resistance to photolysis. Then, the drug-sustained-release paper-based mulch was fabricated by coating ABA@ASL and biofriendly carnauba emulsion on the paper substrate. The paper-based mulch exhibits excellent mechanical and hydrophobic properties, with a dry tensile energy absorption value of 50.98 J/m_², a wet tensile energy absorption value of 17.02 J/m_², and a water contact angle reaching up to 103°. The moisture retention rate of soil 5 cm below the surface, after a 7-day application of paper-based mulch, reached an impressive 73%. Furthermore, the thermal insulation performance of this paper-based mulch was found to be comparable to that achieved with polyethylene plastic film. Additionally, the paper-based film exhibited a degradation rate exceeding 80% after 100 days in the soil burial degradation experiment, owing to the environmentally friendly and biodegradable nature of the bio-based material throughout the entire process.