The invention discloses a preparation method of low-segregation-degree motor rotor microalloy aluminum of a
new energy automobile, which comprises the following steps: (1) preheating a mixture of
titanium,
boron,
silicon, iron,
copper,
magnesium,
zinc and aluminum, charging into a furnace for
smelting, paving a layer of covering agent on the surface, and heating to 670-800 DEG C; (2) adding a refining agent for refining, performing standing and
slag removal to obtain refined melt A; (3) heating the refined melt A to 800-900 DEG C, firstly adding
lanthanum, preserving heat for 15-30 minutes, then adding
ytterbium, stirring, paving a covering agent, preserving heat for 10-60 minutes, and then cooling; (4) when the temperature is reduced to 670-800 DEG C, adding a refining agent for refining, standing, covering and slagging off to obtain refined melt B; and (5) spraying
coating on the inner side of a
casting mold, pouring the refined melt B into the
casting mold, performing centrifugal
casting for 20-40 s, and taking the microalloy aluminum out. According to the method, by adding
lanthanum and
ytterbium, pinholes are eliminated, and the
mechanical property of the microalloy aluminum is improved; and through the regulation and control of each preparation step, the
cooling time is shortened, migration and aggregation of TiAl3 and TiB2 are reduced, and segregation is reduced.