A cloud service integration pay trading system includes a trust certificate platform, an identity provider platform, at least one user terminal and a cloud platform. Each user terminal can log in the cloud platform to purchase services from the trust certificate platform by using a cloud account being registered in the identity provider platform. When in transaction, the request for consumption from the trust certificate platform is transmitted by the identity provider platform to the cloud platform, allowing the user terminal to use the money flow service of the cloud platform to pay the amount charged.