Abstract: In use, the ability of internal endurance of a type nonmetallic frothy pressure part was not changed and the ability of external endurance of that was relatively low. By changing the structure of the part, the influence of ratio of height to diameter on the abilities of internal endurance and external endurance was researched. The results indicated that when the ability of internal endurance of the nonmetallic frothy pressure part was not changed and to enhance the ratio of height to diameter cannot enhance the ability of external endurance.