While the natural ventilation double-skin facade is a widely-used technology, its thermal performance is not yet fully understood. Hence, this paper investigates the thermal performance and optimization of double-skin facades. Previous studies focused on typical moments or standard days to evaluate the thermal performance of a double-skin facade. The current study adopts a simplified method based on Computational Fluid Dynamics (CFD) to obtain the hourly heat gain and total heat gain of a double skin facade for an entire cooling season. The data is then used to evaluate thermal performance. Finally, based on the total heat gain of the double-skin facade with different structural parameters for an entire cooling season, this paper proposes optimization parameters for different climate zones in China. (C) 2017 Elsevier Ltd. All rights reserved.