The invention belongs to the technical field of Ethernet communication, and particularly relates to a monitoring system with a host-standby switching function and a monitoring host thereof. The monitoring host comprises a processor and at least one switching communication module, wherein each switching communication module comprises a network port controller, a change-over switch, a first networkport and a second network port; the first network port is used for being connected to a system background, and the second network port is used for being connected to a monitoring standby machine; oneend of the change-over switch is connected to the first network port, and the other end of the change-over switch is connected to the network port controller and the second network port in a switchedmode; the processor is connected to the network port controller, controls connection with the change-over switch and is used for realizing communication between the first network port and the networkport controller or the first network port and the second network port according to the main and standby states of the monitoring host. The monitoring host is simple in equipment structure, easy to operate and high in reliability. Moreover, multiple switching communication modules can be arranged in the monitoring host, and redundant communication with the system background can be realized.