Repeated tensile experiments were carried out to explore the force-magnetic coupling properties of steel bars. The correlation between stress σ， strain ε， and normal component magnetic leakage intensity B_Z was investigated. The “stress variation parameter” σ_N and the “magnetic leakage intensity variation parameter” B_N were introduced. The results indicate that both ε values and B_Z values are reversible during steel bar repeated tensile processes. The increase in strain amplitude reduces the change rate of B_Z. The fluctuation periods of σ and B_Z are the same， and the fluctuation directions are opposite. The proportional relationship between the stress amplitude and the variation of magnetic leakage intensity at different repeated tensile stages is consistent. The relative deviation rate is less than 9.40%. σ_N is linearly related to B_N with a slope approximating 1.000. It demonstrates the equivalent relationship between the variation rate of the stress amplitude and the variation rate of the magnetic leakage intensity. The simulation analysis coincides with the experimental results.