The invention discloses a macromolecule heat conduction and dissipation blended composite material. The macromolecule heat conduction and dissipation blended composite material is prepared from, by mass, 35-75 parts of matrix resin, 0-10 parts of flexibilizer, 20-50 parts of heat conduction filler, 0.2-1.0 part of antioxidant 1010, 0.2-1.0 part of phosphite ester antioxidant 168, 0.5-1.5 parts of powder surface activation treating agents and 0.5-1.5 parts of lubricant. An automatic preparation method of the macromolecule heat conduction and dissipation blended composite material includes the steps of firstly, conducting surface treating on heat conduction filler for 20 min through powder surface activation treating agents in a high-speed stirring machine; secondly, making the heat conduction filler enter another high-speed stirring machine through an automatic conveying device to be evenly mixed with other materials; thirdly, automatically conveying the mixture obtained in the second step to an internal mixer to be mixed and kneaded for 15 min; fourthly, making the obtained mixture directly enter a double-screw extruder to be extruded and granulated. The prepared heat conduction and dissipation material has the high mechanical property and heat conduction performance, automatic and continuous production is achieved, a large amount of labor is saved, the production period is greatly shortened, the production cost is greatly reduced, and the macromolecule heat conduction and dissipation blended composite material can be widely applied to the fields of LED illumination, electronic electrical appliances, automobiles and the like where good heat conduction and dissipation performance is required.