The invention discloses a MoO2-MoS2 negative electrode material of a sodium-ion battery with a core-shell structure and a preparation method of the MoO2-MoS2 negative electrode material, and belongs to the technical field of preparation of sodium-ion battery electrode materials. The preparation method comprises the following steps: adopting MoO3 as a precursor to carry out oxidation-reduction reaction with S powder and obtain MoO2, adopting an in-situ synthesis method to grow MoS2 nanosheets on an MoO2 template, and forming an MoO2-MoS2 composite material with the core-shell structure. An MoO2 skeleton plays a role in structure support, so that the superimposition of sheet-shaped MoS2 is avoided, the conductivity of the material is improved, and the cyclic stability of the material is also improved. The preparation process is simple and easy to control, the period is short, the energy consumption is low, the repeatability of products is high, the yield is large, and the benefit for large-scale production is achieved. The MoO2-MoS2 negative electrode material prepared by the method has a three-dimensional core-shell structure and also has the characteristics of high specific-discharge capacity, good cyclic stability and the like.