This study investigated the mechanical properties of zinc-5% aluminum-mixed mischmetal alloy-coated steel strand cables (M-C cables) with diameters ranging from 12 mm to 22 mm. A total of 24 tensile tests were conducted to obtain the nominal yield strength, ultimate strength, elastic modulus, fracture strain, and stress-strain curves for M-C cables with varying diameters. The stress-strain curves of the test specimens were fitted using the modified Ramberg and Osgood models to obtain stress-strain models for M-C cables with different diameters. Based on the actual boundary of the cable used in engineering practice, a new finite element model was established with ABAQUS finite element analysis software. Based on the finite element model, the development of the stress in each layer of steel wire, change in the contact pressures between the wires, and the friction energy dissipation between the wires were analyzed with continuous elongation of the cable.