To evaluate the degradation mechanism of anthocyanins and carotenoids from compound fruit and vegetable juice rich in anthocyanins and carotenoids， cyanidin-3-O-glucoside (C3G) and β-carotene was used as the research object. By constructing different simulated systems， the effects of metal ions， pH， sugar species and content on the C3G and β-carotene stability were studied. The results indicated that the thermal degradation of C3G and β-carotene fitted to the first-order reaction models， and the degradation of both components were nonspontaneous endothermic reactions. After C3G and β-carotene were compounded， the stability of anthocyanin did not change significantly while that of β-carotene decreased. In addition， the effects of different sugar types and contents on the thermal degradation of C3G and β-carotene in the simulated compound system were different. The stimulative effects of sugars on degradation of C3G were according to the ascending order: fructose > sucrose > glucose， and the stability of anthocyanins increased gradually with increment of sugar contents. However， the effects of these sugars on β-carotene were not significant， and the stability of β-carotene decreased gradually with increment of sugar contents. The results provided the theoretical basis for the research and development of compound fruit and vegetable juice rich in anthocyanins and carotenoids.