Water-soluble acrylate emulsions are commonly used in cultural heritage conservation, mostly for the reinforcement and bonding of murals, colored paintings, bone relics and lacquerware. The most widely used acrylate emulsions for heritage protection are the Primal, formerly produced by Rohm and Haas. Commercial materials such as Primal AC33, SF016, B60A, WS24 and MC76 have been widely used in the conservation and restoration practice of cultural relics at home and abroad. However, most of the literature reports are restoration cases of direct purchase and use, and their is a lack of systematic scientific performance evaluation research. In this study, we investigated the hygrothermal and UV ageing performance of five commonly used Primal acrylate emulsions, comparing their ageing resistance properties through microscopic morphology, colour change and gloss, etc. Infrared spectroscopy was used to trace the molecular structure changes and absorption peak intensities during UV ageing to explain their degradation mechanisms. The results show that WS24 and B60A have better heat and humidity aging resistance, while SF016 has the worst performance during the heat and humidity aging test. AC33 showed the most obvious color and glossiness changes. UV ageing test revealed that all five materials underwent chain scission reactions during UV irradiation, and AC33 and MC76 had lactones formation. After 4 200 h UV aging, the carbonyl index (CI) of AC33, SF016, B60A and MC76 increased to different degrees, and carbonyl absorption peak (Dt) intensity decreased by 10%~15%. The carbonyl index of WS24 decreased rapidly, and the carbonyl absorption peak intensity decreased by 53%, which was the worst among the five materials in the UV aging test. According to the comprehensive evaluation, B60A has excellent resistance to UV and hygrothermal aging, and is the best Primal acrylic emulsion for cultural relic protection.