The invention provides a coal mine steel wire rope real-time online detection device and method, and belongs to the field of mine lift mechanism online detection. The detection device and method are characterized in that wire breakage or stress concentration of a coal mine lift mechanism steel wire rope is detected online. A steel wire rope detection probe part is designed through a metal magnetic memory detection technology, a detection component does not need to be magnetized, and besides, the defect that magnetization of the detection component is not uniform due to a magnetic flux leakage detection device such as a permanent magnet is avoided. In order to eliminating influences of outside interference on steel wire rope detection signals, the steel wire rope detection probe is designed through a balance and difference method. Interference of outside on steel wire rope defect output signals is overcome, damage of steel wire rope vibrating to the detection device is overcome, and the strength of the detection device is improved. The defect that the traditional magnetic flux leakage detection technology is not uniform in steel wire rope magnetization is overcome. Zero contact between a detection sensor and the steel wire rope can be achieved. The change of the detection liftoff in the real-time detection process is reduced.