The invention discloses a comprehensive monitoring device for an SNMP (Simple Network Management Protocol) and a management method thereof. The comprehensive monitoring device and the management method are applied to the management for comprehensive monitoring system equipment. The comprehensive monitoring device comprises a special sub-device, a software system device, a network device, an NMS (Network Management System) server and an NMS station. The comprehensive monitoring device is characterized in that the special sub-device, the software system device and the network device are all provided with SNMP agency modules; a protocol conversion module is arranged in the software system device; a network management module is arranged in the NMS server; the network management module is connected with the SNMP agency modules through the SNMP and is used for obtaining data and storing the data in an internal memory database; and a human-computer interface of the NMS station is communicated with the internal memory database and is used for obtaining management information. The invention provides a visual method for monitoring the running state of the comprehensive monitoring device to a system manager, so that the fault location and diagnosis are quickly performed, and the working efficiency of the system maintainer and the whole operation management level of the rail transit are greatly increased.