In traditional temple architecture, artisans often rely on experience to formulate pig blood paste—a decorative adhesive mortar—without scientific reference for material proportions. This study employed single-factor experiments to systematically quantify and optimize the ratios of pig blood, lime/oyster ash, and tung oil. Results showed that a 1:1 volume ratio of pig blood to lime provides the strongest adhesion, while a 1:1.25 ratio achieves the fastest drying. The optimal ratio of pig blood paste to tung oil was determined to be 3:1. Based on feedback from artisans following on-site application, the first-generation ready-to-use powdered pig blood paste was innovatively improved through calcination, producing a second-generation product with enhanced storage stability and usability. Performance and weathering tests verified its effectiveness, and the optimized formula was successfully applied in temple mural restoration. Supported by both experimental data and real-world results, this study proposes a simple, eco-friendly, and sustainable material for the conservation of architectural heritage.