In order to solve the problem of volatile organic compounds (VOCs) emission in the open sewage tank of oilfield stations, this work introduces the calculation methods for VOCs, including the material balance method, ground concentration inversion method, emission coefficient method, and analog estimation method. Besides, the recycle of VOCs in different enclosed?sewage pools, such as reinforced concrete, color steel plate, glass steel plate, reverse hanging membrane and full wetted floating cover, were proposed. The results indicate that the material balance method and the ground concentration inverse method are recommended for a more accurate VOCs content calculation. In contrast, the emission coefficient method and the analogy estimation method are more suitable for a rough VOCs content calculation. In the project of the sewage tank, the anti?hanging membrane sealing scheme was suggested, due to its lower cost, convenient construction, good airtightness, and beautiful appearance. A volatilized gas recovery device can be used to collect the volatilized VOCs in the completely sealed sewage tank, because of its advantages in lower cost and a simpler process.