Abstract: Based on the mechanism of magnetoelastic effect, a high energy pulsed magnetoelastic cable force detector was developed to meet the demand for cable force detection of bridges in service. First, a portable pulsed magnetoelastic cable force detection instrument powered by solar energy was designed. The instrument could output high energy spike pulse signals with adjustable voltage in the range of 0-600 V and current peak up to 60 A, to realize full magnetization of cables with different diameters. The instrument mainly included an upper computer (including software), a lower computer of the pulse magnetoelastic instrument with feedback control and an improved magnetoelastic sensor based on multi-core cables. Besides, the loading and unloading tension tests of the 7-core steel strand with a nominal diameter of 17.8 mm were carried out, the saturation magnetization of the strand was realized, the winding efficiency of the magnetoelastic sensor was increased by 8 times compared with the traditional method, and the linear correlation between the traditional cable force characterization parameters and the tension was analyzed. Finally, a parametric, saturated permeability, μ_s of cable force characterization was proposed, which had linear goodness of fit greater than 95% and higher sensitivity (0.05) compared with traditional parameters. By analyzing the tension characterization errors, the parameter shows lower prediction error (3.7%) and hysteresis error (±1.54%) than traditional parameters. The parameter proposed in this paper can provide a characterization method for detecting tension by the pulsed magnetoelastic method.