Buildings generally feature high energy consumption and large carbon emissions throughout their life cycle, and residential buildings account for the highest proportion in the construction industry. Therefore, in-depth research on the calculation methods of carbon emissions and carbon emission reduction strategies for the whole life cycle of residential buildings is of great practical significance for China to achieve the “dual-carbon” goals. Taking a residential building in Chongqing as a case, this paper constructs a carbon emission model through Glodon software to accurately calculate carbon emissions at each stage. This model comprehensively covers the materialization, operation and demolition stages of the building, and includes all-element carbon emission activities involving “labor, materials and machinery”, thus boasting both comprehensiveness and accuracy. Research data shows that the total carbon emissions throughout the life cycle of this building reach 34,448.25 tCO2e, among which the carbon emissions during the operation stage amount to 24,898.3 tCO2e, accounting for the highest proportion (72.28%). By adopting prefabricated components, low-carbon building materials, photovoltaic systems, material recycling and adding carbon sink systems, carbon emissions can be reduced by 12,731.48 tCO2e, with a total carbon reduction rate of 36.96%, significantly lowering building carbon emissions. In summary, this paper provides a scientific basis and theoretical support for the low-carbon development of residential buildings, and plays a positive role in promoting the transformation of the construction industry towards green and sustainable development.