The invention provides a multi-party competing digital asset transaction system and method based on an intelligent contract, and the system comprises at least four types of participating roles: a seller, a buyer, a transaction platform side, and a supervisor, the seller comprises a seller client interaction end, a seller transaction end, and a seller settlement end, and the buyer comprises a buyer client interaction end, a buyer transaction end, and a buyer settlement end. The transaction platform side comprises a transaction platform side client interaction end, a transaction platform side transaction end and a transaction platform side settlement end; the supervision side comprises a supervision side client interaction end, a supervision side transaction end and a supervision side settlement end; the system allows a plurality of exchange institutions, a plurality of financial institutions and a plurality of supervision units to complete transactions on a model, each transaction party firstly searches a required smart contract in a smart contract library of a platform through an interface provided by a transaction platform party, and if the required smart contract library cannot be queried, the transaction party needs to register and provide the smart contract by himself / herself; and the platform operates different smart contracts to realize transaction demands.