The recycling utilization of solid waste is an important technical means for the sustainable development of the cement industry in China. Calcium carbide slag is a special solid waste in China, which can be used for cement production with a great advantage on CO2 emission reduction. With an view to providing methodological and data support for the development of policies in the cement industry, this paper quantitatively analyzes the environmental effects/environmental benefits of the comprehensive utilization of calcium carbide slag in cement kiln by comparing the traditional system of Portland cement clinker completely produced by natural resources with the system of cement clinker produced by calcium carbide slag based on the life cycle assessment (LCA) method given in standards and specifications of ISO 14040 series. The results show that the latter system has a better effect in material saving and carbon emission reduction, will increase the energy consumption in cement production process, and also slightly increase other pollutants (e.g. SOx, NOx, etc.) emission. The GWP, AP and EP indicators of the calcium carbide slag cement clinker system decrease compared with those of the Portland cement clinker system, while other indicators do not differ much or even slightly increase.