Coinversation Protocol is a synthetic asset issuance protocol and decentralised contract trading exchange based on the Polkadot contract chain. It uses the token CTO issued by Coinversation Protocol and Polkadot (DOT) as collateral, and synthesizes any cryptocurrencies or stocks, bonds, gold and any other off-chain assets through smart contracts and oracles. Users can forge a certain synthetic asset by collateralizing CTO or DOT, such as U.S. dollars, and automatically have a long position in the asset. Users can also convert minted assets into other assets through the trading platform, so as to realize the purpose of shorting the asset and longing other assets. The assets minted by all the users correspond to the liabilities of the entire system, and the proportion of each user's liabilities has been determined at the time of forging, so that their respective profits can be calculated. Because such a collateral pool model does not require a counterparty, it perfectly solves the problems of liquidity and transaction depth in decentralised exchange (DEX).