The effect of air pressure (0.01-0.3 MPa) on the detonatability of an aerosuspension of secondary explosive particles at a low mean volume density of the explosive (0.14-1.28 mg/cm 3 ) is experimentally studied. The structure and basic parameters of detonation depending on the explosive density and initial gas pressure are determined, and the mechanism of low-velocity detonation propagation in explosive aerosuspensions is revealed. The lower concentration limits of detonation at different initial gas pressures are found.