Chaotic systems have various advantages, such as unpredictability, non-periodicity, and so on. The algorithm for encrypting digital images using chaotic systems has a large key space, sensitive initial values, and fast encryption speed. Therefore, in this paper, we propose a reversible data hiding in encrypted images (RDHEI) combined with a chaotic system. The algorithm introduced the SHA-256 method to generate the initial value of the chaotic system and the key of RDHEI by manipulating the plaintext image. Moreover, the chaotic system is used to further encrypt the encrypted image after the data hiding in the RDHEI process. The improvement enhances the sensitivity and security of the key and strengthens the image encryption. The experimental results evaluated by histogram, information entropy, correlation of neighboring pixel points, and other indicators show that the proposed algorithm has comparable performance with state-of-the-art and has more intense encryption.