The shrinkage holes（porosities）in an aluminum alloy cylinder block with a large wall thickness were investigated.A series of countermeasures were considered from the formation mechanism of shrinkage holes in the aluminum alloy die-casting parts and the actual shrinkage conditions.First

through increasing the casting pressure from 65 MPa to 90 MPa and increasing thickness of the cake from 25 mm to 30 mm

the effect presents unsatisfactory.Then

the cooling condition of the mold cooling system was modified

and the spraying time of the release agent was increased

however

the effect could be neglected.Finally

combining with the principle of liquid aluminum solidification feeding

two pins in the region of the shrinkage holes were added with rationally adjusting the squeezing parameters

the shrinkage rate was reduced from 5% to 0.2%

achieving the desirable effect.