Abstract: The mining and processing of iron ore is an important source of energy consumption and greenhouse gas emission. In order to reduce the mining and processing of iron ore greenhouse gas emission, the direct and indirect emissions of greenhouse gas should be calculated based on life cycle method. In order to avoid the truncation error produced by the process-based life cycle assessment method, the economic input-output life cycle assessment method has been used to calculate the life cycle energy consumption and greenhouse gas emissions from mining and processing of iron ores in this article. The calculation results show that the energy consumption intensity is 0.089 tce, and the greenhouse gas emission intensity is 2.138 tCO₂-eq. The coal is the main source of greenhouse gas emissions, which is accounting for about 48.1% of total emissions.