The invention discloses a method for preparing a high thermal conductivity electromagnetic shielding material. The method comprises the following steps that firstly, conductive graphite dispersion liquid is prepared with a silane coupling agent as a modifier; then the conductive graphite dispersion liquid is added to a titanium tetrachloride hydrolysate and reacted to obtain titanium dioxide coated conductive graphite; the titanium oxide coated conductive graphite and an epoxy resin adhesive are stirred and mixed uniformly, boron nitride nanosheets are added, and the mixture is further stirredand mixed to obtain composite particles; the prepared composite particles and epoxy resin matrixes are added to a kneader, stirred and mixed uniformly and extruded and granulated by an extruder to obtain a master batch; the obtained master batch, epoxy resin, an anti-aging agent and a crosslinking agent are mixed and added into a mixing mill, the mixture is subjected to mixing processing at 120 DEG C for 5-10 min, and a prepared mixture is extruded and granulated by a twin-screw extruder to obtain the high thermal conductivity electromagnetic shielding material. The high thermal conductivityelectromagnetic shielding material prepared by the method has good shielding performance and excellent thermal conductivity performance and mechanical properties.