A mixed three-phase solidification model based on Eulerian-Eulerian approach and volume average method for macrosegregation is applied to predict segregation in three dimensional ingot of Al-4%Cu aluminum alloy during direct chill casting (DC). In addition to the thermosolutal buoyancy flow, we consider the movement of equiaxed crystal, the capture of the equiaxed crystals by growing columnar tree trunks and the interaction and impingement between columnar and equiaxed crystals in the model. The results show that the cone zone of negative segregation is obviously observed at the bottom of ingot. Negative segregation is also observed adjacent to the center, whereas positive segregation obtained in the center and middle part of the radius. This W-type segregation profile is agreement with measured experimental data obtained from literatures. At the same time, the influence of pouring temperature and casting speed on macrosegregation are studied. It indicates that casting speed has a greater impact on segregation.