In order to study the optimal treatment process of municipal sludge from the perspective of carbon, the environmental impact, resource consumption analysis and carbon emission accounting of the life process of municipal sludge and general solid waste, bituminous coal and rice straw mixed combustion power generation process through Life Cycle Assessment method were analyzed. The three sludge mixed combustion processes were divided into three stages: upstream production, production process and downstream production, and the weights of each environmental impact type were fully considered from the three perspectives of global, regional and local. The calculation results show that the total environmental impact values of the three mixed combustion processes are the largest under the global perspective, which are 0.87,0.12 and 0.09 person·a/t for every 1 t wet sludge treated (moisture content of 65%). Production upstream and production process (power generation stage) are the two main stages leading to environmental degradation. Global warming, acidification and solid waste are the three types of environmental impact that contribute greatly to the total environmental impact. The net carbon emissions of the three mixed combustion processes are 6 522, 742 and 410 kg CO2,respectively.In terms of resource consumption, the resource consumption potential of sludge and general industrial solid waste mixed combustion power generation process is the largest, followed by sludge and bituminous coal mixed combustion power generation process, and sludge and rice straw mixed combustion power generation process is the smallest. On the whole, the sludge and rice straw mixed combustion power generation process is the most environmentally friendly and resource-saving sludge disposal process, which is worth vigorously promoting.