Consumer purchases of circular products help alleviate resource shortages and protect the environment. Therefore, it is necessary to explore the influencing mechanism of consumers' willingness to pay (WTP) for circular products. Based on the framework of the theory of planned behavior, combined with perceived risk, environmental concern, social value, and product knowledge, this study employed the meta-analytic structural equation modeling based on the results of existing relevant empirical studies (32 samples, N = 14,032) to construct an integrated theoretical model of consumers' WTP for circular products. The findings demonstrated support for the integrated framework, and consumer attitude played a significant mediating role in the model framework. Moreover, the results also suggested that national cultures, types of circular products, and types of respondents were potential reasons for the differences in the results of some relevant studies. The integrated theoretical model focused on the difference evaluation and multivariate path analysis of the influencing factors of consumers' WTP for circular products and prospered the explanatory power and predictability of consumers' WTP for circular products.