A method and an apparatus for indicating connection status between a software defined network device and a controller are disclosed. The method includes: transmitting, by the software defined network device, a transmission control protocol message for establishing a connection with the controller; and transmitting, by the software defined network device, a first indication instruction to a light emitting diode, abbreviated as LED, indicator on the software defined network device, in a case that a destination internet protocol address in the transmission control protocol message is an internet protocol address of the controller, and a destination port in the transmission control protocol message is a port of the controller, the first indication instruction instructing the LED indicator on the software defined network device to be in a first state of a first color. The method solves the problem that connection status between the software defined network device and the controller cannot be displayed visually, and achieves visual display of the connection status between the software defined network device and the controller.