The invention discloses an interest rate out-of-date transaction method and system based on a block chain, equipment and a storage medium. According to the method, a technical scheme of combining a block chain with identity authentication and an intelligent contract is utilized, a third-party organization participated in a traditional interest rate off-period transaction is removed, an intermediate process is simplified, direct docking of a transaction enterprise is realized, real financing cost reduction is realized, a convenient financing interest rate is really returned to the enterprise, and the achievement of transactions and the development of the industry are promoted. Moreover, the supervision of the financial market is improved, the credit transparency and information publication of the whole interest rate out-of-date market are realized, the risks of banks and participants are reduced, the interest rate out-of-date transaction matching and transaction realization are optimized, and the open transaction market which is safer, more convenient and more consistent with supervision is created and realized.