The invention discloses a controller based on an ARM chip. The controller comprises a STM32 minimum system, a high-precision clock module, an Ethernet network module and a RS485 communication module, the high-precision clock module, the Ethernet network module and the RS485 communication module are separately connected with the STM32 minimum system, the STM32 minimum system is connected with a computer through the Ethernet network module, the STM32 minimum system is connected with a motor system through the RS485 communication module, and the STM32 minimum system is connected with a signal switch matrix. The invention also discloses a method for controlling a target device by the controller based on the ARM chip. According to the controller and the method, the system is provided with the controller, the controller is connected with the computer, the controller is also connected to the motor system and the signal switch matrix so that the control of the equipment or the system by operation software of the computer is realized, and the controller can be applied to control of equipment including medical equipment, and antenna or antenna measuring equipment as a system controller.