Multi-legal-person joint loan method and system based on block chain and medium

The invention discloses a multi-legal-person joint loan method based on a block chain, and the method comprises the steps: building an alliance chain by a provincial association society, a legal person travel society and a third party, and enabling the provincial association society, each legal person travel society and the third party to use independent blocks; setting at least three account books; providing the provincial association society, each legal person travel society and the third party respectively with an accounting node and a corresponding system preposition, wherein the account recording node is used for executing account recording operation of an account book, and after the account book data of one account book node is updated, other account book nodes synchronously acquireaccount book data update through the alliance chain, then update and modify a system preposed database connected with the account book node according to the account book data, and finally, a legal person society executes real