Compared with the general blockchain,the data stored by the nodes in the high-stability blockchain are more vulnerable to the tamper-proof threat.In order to ensure the security of the data,a simulation study on the tamper-proof of the data stored by the nodes in the high-stability blockchain is proposed.By sliding window segmentation,the data stored by blockchain nodes are divided into multiple sub-sequences.By judging the changing trend of sub-sequences,the characteristic function is given,and the time series composition of the data stored by blockchain nodes is expressed by string.Based on the calculation of variable step size and the calculation of matching measure,the key characteristics of the data stored by blockchain nodes are extracted.Through the encryption of user information,the user's key is generated,and the ciphertext of the data stored by the blockchain node is obtained,thus completing the data encryption.The watermark tamper-proof algorithm is introduced to divide the watermark information embedded in the data.Through the conversion between watermark information and binary information,combined with the scrambling of the matrix,the tamper-proof of the data stored by blockchain nodes is realized.The experiment results show that the method in this paper can effectively prevent the data stored by blockchain nodes from being tampered with,and improve the concealment and security of data.