MnBi2Te4 is an intrinsic magnetic topological insulator discovered for the first time, which has important research significance. In this paper, Er-doped MnBi2Te4 crystal were synthesized by doping rare earth elements in MnBi2Te4 crystal. The Er atom enters the lattice and replaces the Mn site. Considering the long period of crystal preparation process and the existence of impurities such as Bi2Te3 flux in the product during crystal preparation, the crystal preparation process was optimized. XRD analysis shows that the Er-doped MnBi2Te4 crystal prepared by the optimized process has good crystallinity and no impurity phase. The magnetoelectric transport measurement results show that a small amount of Er-doped MnBi2Te4 crystal has enhanced magnetic properties, and the doped samples undergo antiferromagnetic phase transition at 25.2 K. The layer spacing of Er-doped MnBi2Te4 crystal was studied by atomic force microscopy. The layer spacing is an integral multiple of that of single-layer MnBi2Te4. The phonon vibration mode of Er-doped MnBi2Te4 crystal was studied by Raman measurement, and the results show that doping Er is a feasible method to adjust the magnetic properties of MnBi2Te4.