Circulating cooling water is mainly used for the cooling of solution, liquid sulfur and air compressor in natural gas purification plant. In order to prevent the adsorption of water treatment agent by suspension in cooling water, which reduces the agent concentration and application effect, while avoiding the impact on heat transfer efficiency of heat exchanger due to turbidity increase, it is necessary to remove the suspended substances to meet the water quality index of circulating cooling water. Based on the comparison of turbidity removal rate, filtration precision, operation complexity and maintenance costs of cooling water side filter, it is believed that fiber ball filter is more suitable for natural gas purification plant circulating cooling water filtration.