The environmental impact of co-processing with waste clay,spent catalysts,contaminated soil and other industrial waste in cement kilns were assessed by using life cycle assessment (LCA). A life cycle inventory including input and output processes of cement production was established based on inventory analysis. Gabi5.0 software was used to model and calculate the original data to obtain the corresponding environmental impact potentials, and comparisons were made between conventional and co-processing cement processes on global warming potential, resource depletion potential and human toxicity potential. The results showed that the environmental impact values of conventional and co-processing cement processes for per functional unit of cement production were 5.78* 10~(-11) and 5.61 * 10~(-11) respectively. Compared with conventional production process, the lifecycle environmental impact potential of co-processing was reduced by a factor of 2.94%; global warming potential and human toxicity potential made the greatest contribution to environmental impacts in cement production, with decreased environmental impact potentials of co-processing by 0.80% and 1.80% respectively and the decreased environmental impact potential of co-processing on resource depletion by 11.1%; from the view of a whole lifecycle of cement production, clinker calcination ranked the first in environmental impacts, with a reduced rate of co-processing of 8.0% in comparison with the conventional production process. Co-processing has a better environmental performance than conventional production.