Bulk chemical commodity futures trading system and method based on purchase and sale price difference

The invention provides a bulk chemical commodity futures trading system based on purchase and sale price difference. The system comprises a financial module, a special field management module, a transaction module and a settlement module. The special field management module creates a special field, sets price difference transaction rules, creates transaction chains, freezes the sales difference according to the price difference transaction rule; the transaction module completes transaction of the transaction chain in a reverse order; the settlement module calculates transaction surplus of thecompleted transaction, unfreezes the transaction surplus. According to the invention, the requirement on the fund limit of the transaction subject is low; enterprise cash flow occupation is small, itis ensured that different clients deliver according to a unified rule, it is ensured that the same system provides independent transaction and settlement services for different login users, transaction cost can be effectively