Privacy-preserving transactions are currently an important direction for the development of Blockchain. Traditional blockchain transactions record the information of all participants, which leads to privacy leakage of user information and behavior. Privacy preserving methods such as Ring Confidential Transactions lose efficiency, while Zero-Knowledge Proof is limited to the range proof. To fix the aforementioned issues, we propose and implement a high efficiency, strong privacy, and flexible scalability privacy-preserving transactions framework, which adopts a master-slave chain design and supports contract parallelism. By reducing pseudo commitments and the dimensionality of the signature matrix, the transaction efficiency and privacy protection level are improved while ensuring transaction anonymity. Furthermore, the improved scope proof function enables it to provide proof within any range, providing strong transaction supervision for regulatory authorities. Finally, through comparative experiments with well-known privacy-preserving trading projects, the results prove that our method is superior to existing methods.