“…Optimizing Filling Pressure. Mobile phone shell is thin-walled part, the main deformation is warpage [3],we adopt the pressure control method with filling pressure and time, which set up 80%, 100%, 120%, 140% filling pressure. The results show that the larger the filling pressure is, the smaller the volume shrinkage is, when the filling pressure is 120%, the volume shrinkage is 3.827+0.9055=4.7325.As we can be seen in Figure 1, the greater the filling pressure, the smaller the deformation, When the filling pressure is 80%, the deformation is 0.5173-0.1367=0.3806mm,When the filling pressure is 140%, the deformation of all effects is 0.2667 -0.0137=0.253mm, and the deformation decreased by 33.5%, But too much pressure will increase the clamping force, increase energy consumption, count against to enterprise production.…”