The invention discloses a steel 
wire rope magnetic memory on-line detection device, and belongs to the technical field of non-destructive detection. The steel 
wire rope magnetic memory on-line detection device includes two groups of three-dimensional magnetoresistive sensors, adders, multipliers and subtracters, the two groups of three-dimensional magnetoresistive sensors are mounted on a steel 
wire rope and have the same mounting direction, and each group of three-dimensional magnetoresistive sensors comprises 8-12 three-dimensional magnetoresistive sensors uniformly distributed at a same circumference. An equilibrium and differential detection method is adopted to mainly aim to overcome steel wire 
rope shaking and outside interference, secondary output of 
signal characters is carried out, and the accuracy for judging 
metal member defects is improved; secondly, with adopting of a component 
signal single output method, whether a point is a steel wire 
rope defect is judged according to characteristic signals singly outputted by a 
normal component and a tangential component; and then, the two groups of annular uniformly-arranged three-dimensional magnetoresistive sensors HMC1053 are adopted to achieve all-dimensional inspection of the 
normal component and the tangential component of the steel wire 
rope, so as to eliminate the measured blind area problem.