The invention discloses 
silicon dioxide / micro-swelling 
graphite / 
graphite composite heat conduction 
silicone grease and a preparation method thereof. The preparation method comprises the following steps of uniformly mixing micro-swelling 
graphite and graphite by a high-speed mixing 
machine, so as to obtain heat conduction filler for further use; adding the heat conduction filler into an ethyl 
alcohol solution, stirring by ultrasonic 
waves, then adding a 
coupling agent into a reaction kettle, stirring, then adding 
silicon dioxide, and enabling the ethyl 
alcohol to completely evaporate, so as toobtain modified compound heat conduction filler; finally, adding the obtained modified compound heat conduction filler, 
silicone oil, a crosslinking agent, a surfactant and an 
antioxidant into an internal mixer to perform banburying, so as to obtain the composite heat conduction 
silicone grease. The 
silicon dioxide / micro-swelling graphite / 
graphite composite heat conduction 
silicone grease has theadvantages that the surfaces of the micro-swelling graphite and graphite are coated with the surfactant, and the insulation property, heat conduction property, softness, rebound resilience and 
plasticity are improved at the premises of sufficient utilization of heat conduction property; the heat conduction rate of the 
silicon dioxide is high, and the sources are wide; by compounding with grapheneand the graphite, the heat conduction 
silicone grease with 
high heat conduction coefficient, excellent insulation property, high price-to-
performance ratio and wide application range can be prepared.