In order to realize the stable control of rare earth content in rare earth single crystal superalloy and clarify the crucible interface reaction mechanism that rare earth elements participate in the melting process, the effect of melting time on the interfacial reaction of Y-containing superalloy CMSX-4 and Al2O3 ceramic crucible during vacuum induction melting and the residual amount of rare earth Y were studied. The results show that with the extension of melting time, the interfacial reaction becomes more severe. During the melting process, yttrium first reacts with the Al2O3 matrix to form Y2O3, and Y2O3 will continue to react with Al2O3 to form yttrium aluminate reaction layer with different atomic ratios of Y and Al. The final interface reaction product formed on the crucible surface is composed of YAlO3 in the outer layer, Y3Al5O12 (Y3Al2(AlO4)3) in the inner layer and the attached superalloy. The residual amount of rare earth Y in the alloy was 41.023, 4.566 and 5.368 ppm when melting for 10~30 min.