Abstract: The filling mechanism of a new counter-gravity casting method-vacuum various pressure counter-gravity casting thin-wall castings is studied.And the vacuum various pressure counter-gravity casting and the gravity casting to cast 0.8mm、1.5mm、2mm aluminum alloy thin-wall castings were investigated.The study indicated that the vacuum various pressure counter-gravity casting could realize filling mould of metal liquid to stabilize and provided a good condition of the filling mould hydrodynamics.0.8mm、1.5mm、2mm aluminum alloy thin-wall castings of vacuum various pressure counter-gravity casting filled completely and it provided a good capacity of the filling mould.