The invention relates to an Internet payment method and system for a process-type self-service selling machine. The method employing two steps (locking and settlement) solves a problem that the selling price is not determined in process-type self-service selling. The system comprises a self-service APP, the process-type self-service selling machine, a CPS integrated server, and a payment service system. A user obtains the request and response of the self-service selling machine through the self-service APP, and submits the information to the CPS integrated server. The CPS integrated server sends an account fund locking request, and the payment service system carries out the locking of the fund. After the bidirectional verification, the CPS integrated server sends a goods delivery request to the self-service selling machine, and the self-service APP displays a selling process in real time to the user according to the current delivery amount. When the goods delivery is completed, the CPS integrated server sends a fund-unlocking and payment request to the payment service system. The payment service system carries out unlocking and payment, and finally the CPS integrated server asynchronously notifies the self-service selling machine and the self-service APP that the transaction is completed.