The invention discloses a thermoplastic konjac glucomannan/graphene oxide compound material and a preparation method thereof. The invention is characterized in that the compound material comprises the following components according to parts by weight: 1 to 99 parts of thermoplastic konjac glucomannan, 0.001 to 2 parts of graphene oxide, 0 to 10 parts of cross-linking agent and 0 to 10 parts of plasticizing agent; and the preparation method comprises the following steps of: proportioning; adding the thermoplastic konjac glucomannan into an ethanol or water solution of the graphene oxide, stirring for 5 to 10 hours, filtering and drying solid substances; then, drying after stirring and mixing with the cross-linking agent and the plasticizing agent in a mixing machine evenly; and afterwards, placing into a double-screw extrusion machine, extruding after carrying out melt blending at the temperature of 100 to 140 DEG C for 5 to 15 minutes, and granulating so as to prepare the compound material. The compound material has favorable processing performance, has excellent adsorbability, thermal stability and mechanical toughness, can be biologically degraded, can be regenerated, has no pollution to the environment and can be widely applied to the fields of chemical engineering, medicine, environmental protection, capital construction and the like.