S-box is the only nonlinear component in ZUC algorithm, and it plays an important role in the security of the whole algorithm. Chaotic system is widely used in the design of S-box because of its good randomness and high initial value sensitivity. At present, most of the schemes based on chaos to construct S-box use a single chaotic map and cannot generate S-box dynamically. To solve this problem, this paper proposes a scheme of ZUC dynamic S-box construction based on chaotic system. First of all, by iterating the composite mapping in two classical chaotic systems, and introducing the idea of scrambling into the design of S-box, Arnold mapping is carried out on the resulting sequence, which not only increases the nonlinear property of S-box, but also can realize the dynamic generation of S-box. Secondly, the constructed S-box is used to replace the fixed S-box in ZUC algorithm and is applied to resource-constrained IoT devices to encrypt the data of perception layer. Finally, we carry out a large number of experiments, which verify the S-box generated by the chaotic system in this paper is more secure and has a good application prospect in ZUC and other lightweight cryptographic algorithms.