B2B online payment is divided into two parts: online order placement and online payment. An online order is to be placed by the online purchaser of institutional Internet banking after logging on the merchant’s website. After the order is placed successfully, it will be listed an item waiting for payment of the enterprise where the purchaser works, and the financial officer of the enterprise may log on the institutional Internet banking system to pay the corresponding amount of money. Online payment follows the external payment flow of enterprise’s finance office defined by the enterprise, and supports one-stage or multi-stage financial examination flow. After the authorizer of institutional Internet banking grants the authorization, the payment is completed.