The carbon emission from construction sites exhibits distinct traits of spatial concentration and temporal intensity, which underscores the pressing need for effective monitoring and regulation of its environmental impact. However, many construction site carbon assessments are carried out before or after project completion, with little attention paid to monitoring environmental performance during the construction process. This paper developed a performance assessment model called Earned Carbon Value Management (ECVM) based on construction quota theory, cyber-physical system technologies and earned value theory to assess the performance of carbon emissions during construction and to improve the accuracy and efficiency of the carbon emissions management at construction sites. ECVM, with three key parameters and four key indicators, can link the construction carbon emission with the project completion and resource consumption and has. The model has been demonstrated in a construction project in Shanghai. The results show that the model is able to analyze the relationship between construction progress and carbon emissions during the construction process and analyze the causes of deviations and propose targeted corrective measures based on carbon emission performance indicators. The model presented in this paper is generic and can be used for any construction projects that aim to reduce carbon emissions.