The aerodynamic effect or the explosive and shock effect on spinel and sapphire domes of the mid-infrared (mid-IR) imaging missiles are studied. Based on the aerodynamic simulation analysis and the arc wind tunnel experimental results, a protective diamond coating applied to a spinel dome to realize the athermalization design is carried out. To suffer great impact, exciding and spreading experiments testify that a transited structure layer buffer added between the spinel dome and the metal shell could weaken the conducting stress along the shell greatly. The results show that applying spinel instead of sapphire to make domes is feasible under different technique requirements.