Cloud file-sharing systems have become popular as a new issue for files exchanging. However, the free-riders of cloud computing environments make the task of controlling access to share information more difficult, which cannot be avoided by traditional access control methods. In this paper, resource sharing is essential circumstance for information diversty. It is important for the user to develop cloud file-sharing system healthily. Static and repeated evolutionary game models of resource sharing are constructed according to reward and punishment mechanism to improve mutual trust between nodes of cloud system. The results indicate that these mechanisms are effective for improving resource sharing in cloud file-sharing systems.