Abstract: A cloud storage platform data encryption algorithm based on chaotic mapping is proposed. The chaotic sensitivity feature representation method is used to design the unstructured reconfiguration of cloud storage platform big data. The homomorphism transformation and correlation mapping of cloud data are carried out in the unstructured feature distribution space, and the chaotic coding key of cloud data is constructed. The cyclic expansion of data key is carried out by means of symbol adaptive pairing method. According to the intensity of plaintext attack, the encoder protocol of cloud storage platform encryption is constructed in finite domain. The arithmetic coding and cyclic encryption of stored data on cloud platform are realized by piecewise linear coding method. The simulation results show that this method can improve the anti-attack ability of cloud storage platform data, the steganography performance of data is better, and the data encryption storage performance is good.