Combined with the calculation results of combustion products and correlative thermodynamic properties of fog aerosol by CEA(Chemical Equilib rium and Application), the influence of Mg on combustion reaction and visibility light shielding performance was studied. The combustion temperature, linear burning velocity and combustion residue of fog aerosol with different Mg content were tested by infrared radiation thermometer, high-speed camera and X-ray diffraction. The theoretical calculation results show that the composition of equilibrium products includes gas state such as CO₂, CO, H₂O, H₂ and condensed state such as MgO. The experiment results show that Mg plays an important role in the combustion performance and the nucleation process of the coagulant nucleus by control of combustion temperature and linear burning velocity of fog aerosol. The combustion temperature and burning rate increases as the increasing of Mg. The combustion temperature reaches almost 2000 K and burning rate is 1.26 mm·s^-1 as the content of Mg is 8%. When the combustion temperature beyond 1773 K, the nucleation process of chloride finishes thoroughly and the visibility light shielding performance of artificial fog get better gradually. The experiment results are consistent with the theoretical calculation results on the variation tendency of combustion temperature and composition of combustion products, but the combustion residue is much different from the theoretical condensed phase faction.