The invention discloses a mid-set assembly line trolley automatic control system, which comprises electric operation trolleys, a logic control unit, a front-set industrial personal computer, a backstage database, a Web report platform and an automatic control system, wherein the automatic control system comprises a trolley advancing controller, a working position recognition module, a warning light controller and a backstage management host; the automatic control system adopts a single chip microcomputer for driving, a brushless DC motor is adopted for position control, the system control mode is to adopt a set of single chip microcomputer control module for a trolley at each working position to bear the control task, and a distributed control mode of realizing interconnection through serial communication is adopted through control modules. According to the mid-set assembly line trolley automatic control system provided by the invention, the existing mode of advancing by manual pushing is changed into automatic operation, functions of collision avoidance, timing alarming, real-time information statistics and the like are added, the service life of a guide rail is prolonged, the labor intensity of workers is reduced, and the ability of response to sudden problems by the mid-set assembly line is enhanced.