The study addresses the urgent need to protect architectural paintings at the Foguang Temple. These ungrounded paintings face much damage, including the peeling off of pigments, fading and cracking. Orthogonal experiments were done on entailing compounding of two traditional protection materials:the gum of Bletilla striata (Thunb) Rchb. f. and fish collagen. These experiments show that the best formula for strengthening and protecting architectural paintings with no plaster layer is (weight percentile):3% fish collagen and 0.1% gum of Bletilla striata, as the effective reinforcement ingredients, coupled with 0.5% fungicide (PTA), 0.1% of UV absorbers (BP4) and 0.1% antistatic agent. This formulation shows excellent performance in terms of reinforcing, antifungal and antiUV aging properties. This is a good choice for the reinforcement and protection of the architectural paintings at the Foguang Temple and other similar sites.