A human-machine interface (HMI) system comprises a local operation device, a display device, a HMI display control device and a communication control device. The local operation device generates a local operation signal. The display device shows a display image corresponding to a display signal. The HMI display control device generates the display signal according to the local operation signal or a remote operation signal. The communication control device comprises a wireless communication connection port for connecting with a remote operation device. The communication control device transmits the local operation signal to the HMI display control device, transmits the display signal to the display device, and selectively transmits the display signal to the remote operation device. The communication control device outputs the remote operation signal to the HMI display control device when the communication control device determines itself receives the remote operation signal but does not receive the local operation signal.