Abstract: For the crack and filling defect on the top part of lead brass underwater breathing valve blank, process optimization from prospect of blank structure and technological parameter was carried out. The effects of the technological parameter of die temperature, blank temperature, punch velocity and friction coefficient were analyzed by using Deform-3D software and orthogonal test. The result shows that the die temperature of 250 ℃, blank temperature of 820 ℃, punch velocity of 90 mm/s and friction coefficient of 0.2 have a good effect. After experimental verification, the optimized valve blank has good mold filling effect, and the fine equiaxed grains are obtained on its surface.