The invention discloses a method for preparing a porous carbon loaded stannic oxide composite material. The method comprises the following steps: dissolving citric acid, PVP and NaCl in deionized water, so as to form a transparent solution, and performing freeze drying, so as to obtain white powder; calcining the white powder for the first time, performing suction filtration with deionized water,and performing freeze drying, so as to obtain porous carbon; dissolving inorganic tin salt in ethanol, so as to form mixed liquor, adding the porous carbon into the mixed liquor, performing ultrasonicstirring, and then calcining for the second time, so as to obtain the carbon loaded stannic oxide composite material. According to the method, stannic oxide particles are uniformly adhered to the surface of porous carbon, so as to form a porous electrode material, the material has the characteristics of high specific surface area and porous structure, is beneficial to the diffusion of Li+, transfer of charge and release of volume expansion, and obviously enhances the electrochemical performance of a negative electrode material. The composite material prepared through the method is simple to operate, uniform in adhering, high in capacity and coulombic efficiency and good in cycling stability when serving as a lithium ion battery negative electrode material, and low in production cost.