The invention belongs to the technical field of switch control, and discloses an automatic change-over switch and a control device and control method for the automatic change-over switch. A voltage detection module detects the voltages of a common power supply and a standby power supply; a main control module is connected with the change-over switch by a wireless signal through an Internet of Things module; a switching judgment module judges whether a multi-path power supply voltage meets the control requirement of a driving mechanism or not, detects whether a power supply automatic conversionrequirement exists or not in real time, and detects whether a power supply fails or not; a switching module switches the power supplies according to a judgment result of the switching judgment module; and the detected information is displayed through a display module. Intelligent switch control is established; meanwhile, synchronous capture switching is preferentially adopted, impact borne by a power grid and equipment thereof is reduced, the closing voltage of a closing circuit breaker is reduced, the safety of the power grid is improved, the service life of the equipment is prolonged, and the adverse effect of power supply quick switching on the power grid and the equipment is minimized.