This paper firstly in detail presents the operating principle and structural design of the new offshore hydration separator. This device can be used to separate hydration and liquid form natural gas without using chemicals, and there are some benefits including compact structure, small floor space, no chemical pollution and high separating efficiency. The swirl characteristics and the resistance characteristics of cyclone have the important impact on the dehydration performance of wet-gas recycling supersonic separator, two experimental rig of the cyclone separator A and B were constructed and systematic dehydration performance experimental investigations of wet-gas separator individual with cyclone A and B were carried out. To find the better cyclone design with small flow resistance, high swirl strength, high separation efficiency. The experimental results showed that the recycling separator with cyclone A has the higher separation efficiency, so comparing with the resistance characteristic, the swirl characteristics has the greater impact on the dehydration performance of the recycling separator. With the better swirl characteristics of the cyclone, the better dehydration performance of the recycling separator. The recycling separator has the better dehydration performance with the better swirl characteristics cyclone.