The utility model provides a security protection monitored control system of gas and steam combined cycle natural gas voltage regulating station, includes access control system, video monitored control system, fire alarm system, main control terminal, access control system and video monitor system all insert main control terminal through a plurality of nodes, reach main control terminal on after video monitor system handles the video data who obtains, main control terminal and fire alarm system communication are connected. The utility model discloses the long -range integration control of system implementation, access control system is two door interlocking access control system, the interlocking is given to the twice door, trail or the order entering with convenient control effectively, and video monitor system is the linkage monitoring system, the system carries out the pertinence analysis to on -site image, it links to produce inside alarm signal according to the rule of setting for, through the automatic presetting bit who gos to the warning to and correspond of coordinated control camera, with this alert area territory realtime graphic automatic display to the corresponding analog display ware, and activate the alarm video recording.