The invention discloses a preparation method of a carbon coated sodium vanadium phosphate composite cathode material. The preparation method comprises the following steps: firstly, performing mixing reaction on a phosphorus source and aqueous solution containing a vanadium source, so that a reaction liquid A is obtained; secondly, performing mixing reaction on a material and reducing sugar, so that a reaction liquid C is obtained; when the phosphorus source does not contain sodium atoms, the material is obtained by performing mixing reaction on the reaction liquid A and a sodium source; and when the phosphorus source also contains the sodium atoms, the material is the reaction liquid A; and thirdly, performing spray drying on the reaction liquid C, and calcining, so that the carbon coatedsodium vanadium phosphate composite cathode material is obtained. In a preparation technology of the invention, the traditional long-time high temperature calcining in the later stage does not need tobe performed, energy consumption is obviously reduced, and large-scale production is easy to realize; the obtained material has good consistency, particle size is 2-20[mu]m, specific capacity is high, rate capability is excellent, charge and discharging cycling stability is good, electrochemical performance and energy density of a battery are improved, practical development of a sodium ion battery is benefited, and the preparation method disclosed by the invention can be applicable to commercial large-scale production and has a broad application prospect in the field of large-scale and high-power battery energy storage.