The invention discloses an automatic vending system and method. The system comprises a server and a plurality of terminal devices. The terminal devices and the server are connected through a wired network or a wireless network. A switching door and a plurality of goods shelves are arranged on the terminal devices. Each goods shelf contains goods of a single variety. The goods are valued according to the number or the weight. Each terminal device comprises a control unit, an input unit, an execution unit, a weighing unit, a paying unit and a communication unit, wherein the control unit is electrically connected with the input unit, the execution unit, the weighing unit, the paying unit and the communication unit; the automatic vending system has the advantages that the consumer shopping habit is better met, and the consumer purchase convenience is improved; the manual work and rent cost are lowered, and therefore the commodity selling price is lowered; the goods of each variety can be displayed in batches for selection by consumers, and the consumers can shop before paying a bill.