Abstract: Water saving and optimization of cooling water system are extremely significant for coal chemical projects. This paper studies the water consumption , electricity consumption, total investment and operating cost of 6 kinds of water cooling system, and builds two tech-economic analysis models about minimum total cost and industry water consumption threshold. Then, the paper sorts the total cost of water cooling systems and improves the solutions to meet the requirement of water consumption standard. At last, the paper makes recommendations for process water saving by sensitivity analysis.