Abstract: To study the effect of oxygen volume fraction on the explosion characteristics of silo coal, an experiment was conducted on the explosion parameters（maximum pressure p_max, maximum pressure rise rate （dp/dt）_max , and explosion index Kst ） of mixed coal in silos with two calorific values and oxygen volume fractions of 21%, 15%, and 10% using a 20 L spherical explosion device. The effect of oxygen volume fraction and calorific value on explosion characteristics was analyzed. The results indicate that: first, when the concentration of coal dust increases, the explosive characteristics of mixed coal with three distinct oxygen concentrations increase first and eventually fall; when the oxygen volume fraction decreases from 21% to 10%, the explosion parameters of mixed coal decrease significantly, and the pmax peaks of mixed coal with two calorific values decrease by 38.9% and 44.8%, respectively, compared with that in air, and（dp/dt）_max dropped by 68.5% and 81.1%, respectively; the explosion risk decreased from high and moderate to weak; second, as the oxygen content decreases, the coal dust concentration of the pmax and（dp/dt）_max peaks of mixed coal changes. The lower the oxygen concentration, the lower the concentration of pmax and （dp/dt）_max peaks of coal dust. Finally, the calorific value has a substantial impact on the explosion properties of mixed coal. The higher the calorific value, the larger the explosion risk, and under conditions of low oxygen and higher coal dust concentration, the coal with a high calorific value has a smaller explosion risk than coal with a low calorific value.