The invention discloses an MoS2/C lithium ion battery cathode composite material synthesized by taking carbohydrate as a carbon source, and a preparation method for the MoS2/C lithium ion battery cathode composite material. The MoS2/C lithium ion battery cathode composite material is prepared from sodium molybdate, thiourea carbohydrate and deionized water through a hydrothermal reaction. Compared with the conventional lithium ion battery cathode composite material, the MoS2/C lithium ion battery cathode composite material has the following obvious advantages: a), the preparation raw materials are low in cost, easy to purchase and high in cost performance; b), the preparation process reduces the raw material losses, and is easy to operate and realize industrial production; and c) the energy transformation ratio of the prepared battery is higher.