To produce high-quality slurry fuel from petroleum coke and municipal sludge, the effects of various biomass materials on slurry characteristics were investigated experimentally. The biomass materials used in this experiment were classified into three categories: monosaccharides (e.g., glucose), starch-based biomass (e.g., potato residue), and cellulose-based biomass (e.g., corn straw, water hyacinth, rice husk, and kelp). The results revealed significant variations in slurry properties influenced by different biomass types and their respective proportions. Increasing the biomass content led to a decrease in the solid concentration of bubble petroleum coke sludge slurry (bubble-PCSS). However, the reduction was moderate with monosaccharides and starch-based biomass, whereas it was pronounced with cellulose-based biomass, especially in kelp. The addition of biomass significantly improved the pseudoplastic rheological properties of the slurry. Specifically, when monosaccharides and starch-based biomass were incorporated, the flow characteristic index approached 0.7. Optimal stability of bubble-PCSS was achieved at a 2% addition level of monosaccharides and starch-based biomass. In contrast, when using cellulose-based biomass such as kelp, water hyacinth, corn straw, and rice husks, they required a 3-4% addition level to reach optimal stability, which was somewhat less favorable than that achieved with monosaccharides and starch-based biomass.