Blockchain ledger is open and transparent. Some attackers can obtain sensitive information through analyzing the ledger data. It causes a great threat to users’ privacy preservation of transaction. In view of the importance of blockchain transaction privacy preservation， the causes of the transaction privacy leakage were analyzed at first， and the transaction privacy was divided into two types： the transaction participator’s identity privacy and transaction data privacy. Then， in the perspectives of these two types of transaction privacy， the existing privacy-preserving technologies for blockchain transaction were presented. Next， in view of the contradiction between the transaction identity privacy preservation and supervision， transaction identity privacy preservation schemes considering supervision were introduced. Finally， the future research directions of the privacy-preserving technologies for blockchain transaction were summarized and prospected.