The invention discloses a method for preparing silver nanowire-graphene composite aerogel. The method comprises steps as follows: 1) preparation of a graphene oxide aqueous solution: graphene oxide sheets are added to water for mixing, and the graphene oxide aqueous solution with the mass concentration being 0.5-10 mg/mL is prepared; 2) a silver nanowire solution with the mass concentration being 1-20 mg/mL is added to the graphene oxide aqueous solution prepared in the step 1) for mixing, and a mixed solution is prepared; 3) a reducing agent is added to the mixed solution, the reducing agent and the mixed solution react in a closed container, and hydrogel is prepared; 4) the hydrogel is cleaned and dried, and the aerogel is prepared. The particle size of a silver nanowire-graphene composite aerogel material can obviously reduce volume shrinkage of the hydrogel, a large quantity of high-activity silver nanoparticles are loaded in graphene, and the material has the advantages of ultra-large porosity, low density, large specific surface area, adjustable shape, simple preparation process and the like.