The invention discloses a real-time on-line detection 
system for tension of a steel 
wire rope for an 
elevator. The detection 
system comprises a 
cloud server, a sensor, an information collection board, an 
intelligent decision-making terminal, a hand-held monitor and an 
elevator system, wherein the sensor monitors the tension for dragging the steel 
wire rope in real time and online displays a numerical value of the tension received by the steel 
wire rope, so that all the tension for dragging the steel wire 
rope is conveniently adjusted to be uniform, the service life of the steel wire 
rope is prolonged, and the 
elevator running comfortableness is improved; by monitoring the change of the numerical value of the tension for dragging the steel wire 
rope in real time, whether there are persons in a car can be determined, and a weighing function of the elevator is realized; the 
intelligent decision-making terminal receives data, makes a local decision according to set logic, and controls the elevator to emergently stop running or stop running after the elevator stops nearby in an abnormal state, thereby avoiding sudden accidents; and the 
cloud server collects historical 
big data, performs comparison, analysis, judgment and depicts a change trend of the tension of the steel wire rope, and if the trend becomes bad, a preventive and targeted maintenance service can be performed, thereby improving a 
safety coefficient of elevator running.