In the magnetic mixing frequency detectionof ferromagnetic materials, the excitation parameters of high and low frequency magnetic fields directly relate to the intensity and sensitivity of magnetic mixing frequency effect. Aiming at the magnetic mixing frequency detection issue of the hardness of ferromagnetic materials, the uniform design method is used to study the influence of excitation parameters on magnetic mixing frequency effect. Based on the fuzzy theory, a fuzzy evaluation model of mixing frequency effect with two characteristic indexes of variation coefficient and correlation coefficient is established. On this basis, the influence law of magnetic mixing frequency excitation parameters on the mixing frequency effect is obtained through regression analysis.The excitation parameter combination that can obtain strong magnetic mixing frequency effect is optimized. The optimization results show that the selection of the mixing frequency excitation parameters has a great influence on the magnetic mixing frequency effect.Using the optimized excitation parameters can obtain stronger mixing frequency effect and greatly improve the sensitivity of mixing frequency detection.The research work effectively promotes the application of magnetic mixing frequency detection technology in the field of nondestructive testing.