This paper utilizes wireless radio frequency identification (RFID) readers and IoT sensors to monitor and collect relevant data during the construction phase. Taking the construction process of prefabricated buildings as an example, by systematically organizing data on carbon footprint factors such as energy, building materials, transportation, machinery shifts, and labor days, a carbon emission calculation model for the materialization stage of prefabricated buildings and a projection tracing clustering analysis method were established. Subsequently, a carbon emission calculation model for the construction process, including two stages—building material transportation and on-site construction—was constructed to quantitatively analyze carbon emissions during the construction phase of building projects. The results indicate that carbon emissions vary significantly among different residential buildings, with the production stage of building materials accounting for the largest share of carbon emissions (approximately 90%) in all processes. Additionally, taking prefabricated buildings as an example, materials are the primary factor contributing to carbon emissions during the construction stage, also accounting for over 90%. Furthermore, during the entire construction phase, the main structure is the primary carbon emission factor, accounting for over 70% of carbon emissions. Based on the carbon emission calculation framework, the primary causes and main elements of carbon emissions during the construction phase can be calculated and analyzed. By optimizing construction processes and adjusting construction techniques, carbon reduction and control effects can be achieved.