The analysis of carbon emissions during the construction period of T-beam bridges can provide theoretical basis for low-carbon construction of bridges. This paper first defines the boundary of carbon emissions calculation during the bridge construction period, and divides the construction period into three stages: material production, material transportation, and mechanical construction. The carbon emission model of the bridge construction period is established by using the factor decomposition theory and the carbon emission coefficient method. Taking a section of prefabricated T-beam Bridge from Yiyang to Loudi Expressway as the research object, various carbon emission factors were determined through inventory, valuation documents and construction drawings, and the carbon emissions of the superstructure were calculated. Based on this calculation method, T-beam bridge was calculated. The carbon emissions of various parts of the bridge were compared and analyzed. Finally, the uncertainties of the influencing factors in this carbon emission model were also taken into account. The sensitivity analysis of the parameters was performed. The results show that: During the construction period of T-bridge bridges, the main sources of carbon emissions are the main source of the structure, the pile foundation works and the upper part of the project; at the construction phase, they mainly come from the production phase; the carbon emission parameters of the T-bridge bridge construction period are sensitive to the intensity: cement carbon Emission Factor＞ Steel Carbon Emission Factor＞ Electricity Carbon Emission Factor＞ Diesel Carbon Emission Factor. The conclusion of this paper provides a reference calculation model for the carbon emissions generated by the T-beam bridge and provides a reference for the construction of low-carbon bridges.