The effect of different electric pulse parameters which include capacitance, voltage, frequency and treating time on the hot galvanizing coatings was studied through orthogonal test of array L25. For each factor, five levels were chosen to cover the experimental region. Results showed that the thicknesses of ally layer with different parameter were all reduced. It is from 63.57μm to 28.49μm. The intuition analysis of orthogonal test derived that the pulse capacitance had the most significant influence on the growth of alloy layer, and the influence of other factors was little. The optimum parameter combination were the capacitance of 200μF , the voltage of 700V, the pulse frequency of 4 Hz, and the treating time of 30 s.