In this study, demethylated-acylated enzymatic hydrolysis lignin (DAEHL) with excellent solubility in castor oil and antioxidant activities were prepared via the tandem modification strategy. First, iodocyclohexane simultaneously achieved β-O-4 breakage and hydrogenation, which enhanced the antioxidant activity of lignin. Furthermore, the acylation reaction by palmitoyl chloride increased the alkyl content in the lignin, which can improve the solubility of lignin in castor oil. The structural evolution of lignin showed the change in the hydroxyl group content, which induced a change in the solubility and antioxidant activity of the lignin. 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) ammonium salt (ABTS) radical scavenging, Fe