The invention provides an automatic trading system. The automatic trading system comprises a self-service device for self-service operation of a user, a control device capable of controlling the self-service device, and an upper processing unit for comprehensively processing the self-service device and the control device. The system is characterized in that based on a user level database which correspondingly stores the user identification ID information and the user level, the user level corresponding to the user identification ID information is discriminated; the authentication level of an authentication unit is changed according to the user level; the higher the user level is, the lower the authentication level of the authentication unit is; and the lower the user level is, the higher the authentication level of the authentication unit is.