The impact of pneumatic pressure for a supersonic conformal dome on optical and structure characteristics was studied. The elliptical dome with a diameter of 203 mm and the ratio of length to diameter of 1∶1 was designed. Wind tunnel experiments in an attack angle 0′ were accomplished by speeds of 2.0, 2.5 and 3.0 Ma and the pressure was obtained on the surface of dome. The displacement distribution and the stress distribution of a hot-press MgF2 dome were obtained by the fluid-structure coupled analysis on the finite element model based on different thicknesses. According to the data, the figure curves of these dome models were fitted renewedly. Imaging quality was compared based on the optical system designed and the results illuminate that the maximum stress is 37.5 MPa when the thickness of the dome is 2 mm and the speed is 3.0 Ma. At the same time, by contrast with the initial optics of the dome, the relative error of spot radius is 0.26%, and figure relative error is -1.03%, which meets the requirements of structure strength and imaging quality under the dynamic pressure.