The central counterparty (hereinafter referred to as CCP) refers to the legal counterparty as an original market participant who participates in the transaction settlement, acts as the seller of the original buyer and the buyer of the original seller, and ensures the execution of the transaction. Its core content is contract replacement and guarantee settlement. Contract replacement means that the original contract between the buyer and the seller is replaced by the contract between the buyer and CCP and the original contract is cancelled accordingly; Guaranteed delivery means that CCP must guarantee the normal performance of the contract under any circumstances. Even if one party in the sales fails to perform the contract, CCP must first perform the delivery obligation to the observant party, and then pursue the liability for breach of contract from the defaulting party.