Method for solving shrinkage casting defects at rim/spoke junction of magnesium alloy hub

A method for solving shrinkage casting defects at the junction of a rim and spokes of a magnesium alloy hub comprises the following steps that (1) a magnesium alloy hub die is prepared, specifically, a metal die for low-pressure casting or gravity casting of the magnesium alloy hub is prepared according to a conventional method, and the metal die is composed of a bottom die, a side die and an upper die; a self-feeding riser is arranged in an area corresponding to a rim/spoke junction, namely a hot spot, on the upper die, and a heat preservation insert is arranged in the middle of the position, corresponding to the self-feeding riser, of the upper die; (2) pouring a magnesium alloy hub, wherein magnesium alloy melt pouring is completed after a metal mold is preheated; and (3) mold opening and part taking are conducted, specifically, the mold is opened after the magnesium alloy hub casting is completely solidified, and the casting is taken out. The industrial problem that in existing gravity casting and low-pre