The thermal and pressure conditions on the launch container skin surface are studied by Fluent software, in which three typical sizes of launch containers are chosen. Aluminum samples are employed as a launch container skin example, and their mechanical property impairment are researched in ablating test during thermal launching. The results show that mechanical properties of aluminum samples decrease little as the erosion time increases to 1.5 s. But when the erosion time increases to 2.0 s, the aluminum samples lost their mechanical properties completely. The results support important data for lightly designing, protection designing and number times of use designing of container launches which made of aluminum alloy materials.