This study proposes a two-layer collaborative approach for privacy protection in consortium blockchain. The proposed approach consists of two layers. 1. Inter-chain privacy protection: such protection approach aims to protect the privacy between different businesses. This approach is realized by separating and storing the data of different businesses. 2. Intra-chain privacy protection: such protection approach is realized by embedding collection field into transaction body to specify the participants of privacy protection. Then, this approach regards the receiving blockchain node as a relay node to synchronize private data. At the same time, the relay node is also responsible to construct a public transaction by replacing the private payload with its hash after which the public transaction will be synchronized to all participants through consensus. Finally, private participant nodes update their private ledgers to achieve intra-chain privacy. To verify the validity of the proposed approach, some experiments are designed to measure the throughput of inter-chain privacy protection and the delay of intra-chain privacy protection. The experimental results show that the privacy protection approach which is combined with coarse-grained inter-chain protection and fine-grained intra-chain protection ensures the considerable performance and satisfies the privacy requirements at the same time. Thus, the proposed approach has made a potential contribution to the privacy and security of blockchain platform.