After the expansion of its production capacity, a petrochemical company faced a shortage of water resources. This problem was resolved after the application of the dual-membrane technology of “ultra-filtration followed by two stages of reverse osmosis”. This paper introduces the application and operation of dual-membrane process in recycling and reuse of reclaimed water, and highlights the issues and problems encountered in operation and design of this dual-membrane solution. This dual-membrane process has the advantages of occupying smaller plot size, simple to operate and easy to implement automated process control. It also has broad application prospect in the recycling and reuse of reclaimed water from brackish water. From operation experience of this process facilities, it is optimal to control the primary reverse osmosis recovery rate at 70%~75%, and the secondary reverse osmosis recovery rate should not be greater than 80%. The application of this process provides a reference for future projects of the same nature.