The underlying architectures of blockchain are different， with each single chain developing in parallel and unable to interact with other chains， forming their own value systems. This means that asset transfer and value circulation cannot be achieved， resulting in “value island”. A multi-notary consensus cross-chain method based on Elliptic Curve Cryptography （ECC） was proposed to address the current issue of low blockchain cross-chain success rate. Firstly， two blockchains were built and multiple notaries were introduced. Secondly， cross-chain information interaction was carried out to enable multiple notaries to reach consensus on the relevant information of cross-chain transactions. Thirdly， in the process of consensus among multiple notaries， encryption algorithms were introduced to ensure the security of messages， and the concept of earnest money was introduced to prevent notaries from committing wrongdoing. Finally， the influence of 5%， 10%， 15%， and 20% malicious notary nodes on transactions was tested respectively. Experimental results show that under conditions with 5%， 10%， 15%， and 20% malicious notary nodes， compared to the single signature notary cross-chain （no malicious notary） method， the proposed method improves the cross-chain success rate by 9.39， 2.05， 3.66， and 13.58 percentage points， respectively； compared to the in-chain transaction method， the proposed method improves the cross-chain success rate by 6.33， 5.10， 4.75， and 38.89 percentage points， respectively； compared to the cross-chain method of multiple signature notaries， the proposed method improves the cross-chain success rate by 12.42， 7.53， 16.89， and 23.57 percentage points， respectively. It can be seen that the proposed method promotes the interconnection of blockchain networks， and strengthens asset liquidity and value exchange capability.