Lignin-derived biochar materials with acid functional groups (-COOH, –SO3H and –OH) were synthesized by carbonization of lignin (LigT) at T = (300, 400, 500) °C and mix ball-milling of the carbonized solids with thiomalic acid and partial oxidation of the functional solids with H2O2. Mix ball-milling promoted interactions between biochar CO and alkoxy C–O groups and thiomalic acid –COOH groups, which allowed H2O2 to convert covalently-bonded sulfur-containing functional groups on the biochars into Brønsted acid sites. The lignin-derived biochar solid acid materials were applied as catalysts to convert fructose into 5-ethoxymethylfurfural (EMF) and ethyl levulinate (EL) via 5-hydroxymethylfurfural (HMF) intermediate in ethanol solvent. Yields of HMF, EMF and EL reached 11%, 62% and 22%, respectively at 115 °C and 6 h with 100% conversion of fructose when the reaction was conducted with Lig300(S/C = 2)-SO3H, which had the highest total acidity in this work. The activation energy (70.9 kJ/mol) for conversion of fructose into HMF was lower than that for conversion of HMF into EMF (90.2 kJ/mol). The method for synthesizing sulfonated-containing biochars is green and efficient and the lignin-derived biochar solid acid catalysts are effective for converting renewable resources into platform chemicals.