Abstract: The article introduced the current hazards of volatile organic pollutants and its treatment methods.Based on the purification requirements of organic waste gas produced in the casting process of an enterprise in Jiangsu Province,the three-tower RTO purification research and design was carried out as well as the process design,key parameter calculation,equipment selection and verification.Under the conditions of 760℃combustion chamber temperature and 1.0s residence time,the average RTO exhaust temperature is 98℃,the heat recovery efficiency is 93.2%,the treatment efficiency is 98.7%,and the total non-methane hydrocarbon emission concentration is 18.6 mg/Nm³,which meets the requirements of local emission standards.This design example provided certain reference value for standardizing the design of RTO industrial organic waste gas purification system and had positive significance for promoting carbon reduction work.