The invention discloses an instant WeChat payment method for petroleum marketing, which comprises the steps that a remote payment management system is logged in, and the remote payment management system verifies and sends a receipt message; a WeChat payment platform is entered, and the transaction amount is inputted; the WeChat payment platform generates corresponding two-dimensional code identification; the remote payment management system receives the payment and sends a paid message to the WeChat payment platform; and the WeChat payment platform prints a consumption bill and sends a receipt to the remote payment management system. The payment system comprises a remote payment management system, a WeChat payment platform, a mobile terminal and a POS machine. The method and system disclosed by the invention solves problems that the number of transaction of traditional petroleum marketing is large, the waiting time of people is long, the accumulated amount of transactions is too great, and a careless mistake occurs easily in transaction settlement, functions of instant WeChat payment and card swiping payment, the transaction time is short, and a problem of change is not involved.