Firstly, the influence of building design factors on building carbon emissions was analysed, and the influence of building form factor, building orientation and building envelope on building carbon emissions was simulated and studied, which shows that the south-facing direction has the lowest building carbon emissions, the external window shading factor is negatively related to building carbon emissions, and all other factors are positively related to building carbon emissions. The existing low carbon evaluation systems were then analysed, most of which suffer from a lack of carbon emission calculation methods and a lack of comprehensive scoring methods. This paper establishes an evaluation index system based on the principles of evaluation system construction, determines the benchmarks for index evaluation based on energy saving standards and research data, delineates the range of evaluation index parameters and the percentage of scores, and establishes an evaluation index system. The weights of the evaluation indicators were calculated using hierarchical analysis and combined with expert questionnaires, and a comprehensive scoring method was established based on the weights to build a building carbon emission evaluation system.