The invention discloses a real-time transmission-line live working safety control system and a working monitoring method. The systems is a real-time live working safety distance detection system based on fusion of multiple ultrasonic sensors. According to specific line conditions, information of distance between an operator and a danger point is calculated in real time according to various limb actions of the operator and the minimum safety distance of live working, timely analysis is made, the operator is reminded of paying attention to the distance between all the parts of the body and the corresponding danger points, real-time position of the operator is transmitted to a monitoring center by real-time image monitoring, and the system can give an alarm signal in real time once the operator is about to reach the danger position point. Effective monitoring is provided for safety of live working, and the system and the method have significant engineering practice value to prevention or reduction of personal electric shock accidents of live working.