To further study the combustion characteristics of magnesium metal particles, based on the Arrhenius law, a one-dimensional spherical symmetric quasi-steady combustion model of limit reaction rate of magnesium particle was established. The combustion process of a magnesium particle with a diameter of 120 μm was simulated in the atmospheric environment. The combustion field temperature distribution, composition distribution of reactants and combustion time of particle were obtained. Results show that the highest temperature obtained by the limit-rate combustion model in the reaction zone is 3568 K, and the combustion time of magnesium particle is 21.9 ms. The calculated results agree well with the experimental in literatures. Reactant of oxygen and magnesium vapor can spread to the outside of the reaction zone, which is qualitatively in accordance with the experimental phenomenon that oxygen atoms are detected in the quenched magnesium particle, indicating that the limit-rate combustion model can describe more precisely the actual condition of magnesium particle combustion than traditional fast-rate combustion model.