Concerning the low efficiency of data update and low security of mobile terminal, a storage and segmentation encoding technology was proposed. Firstly, the data of mobile terminal was equally segmented and stored in cloud,then each segment of data was marked by coding techniques; secondly, the corresponding data block information was downloaded to update when users update the data; finally, the updated data was re-encoded, and cryptographically uploaded to the cloud in appropriate position to form a complete data to be stored. The experimental results show that compared with traditional mobile security solution including Advanced Encryption Standard (AES) scheme and Regenerating Code (RC) coding technique, the proposed model can save file conversion time when the data is updated frequently in cloud, and significantly reduce the performance overhead of the mobile terminal. The proposed model can significantly improve the efficiency of updating data and resource utilization rate of mobile terminal, and effectively strengthen the confidentiality and integrity of mobile cloud data,it has obvious advantages for the demand of updating mobile terminal data frequently.