The invention discloses a supported nano-metal catalyst for preparing arene by catalytically reforming light naphtha, and relates to the technical field of chemical separation. The catalyst is prepared from the following raw materials in parts by mass: 90 to 100 parts of activated carbon, 15 to 20 parts of platinum nano-powder, 8 to 10 parts of nickel powder, 5 to 8 parts of clay, 3 to 6 parts of a competitive adsorbent, 120 to 130 parts of a nitric acid solution and 50 to 60 parts of de-ionized water. According to the catalyst, citric acid-modified activated carbon is taken as a carrier, platinum is taken as a major active ingredient, nickel is taken as an auxiliary active ingredient, and clay is taken as an adhesive, so that the prepared catalyst has the characteristics of high selectivity and high catalysis efficiency, and the yield of arene can be increased.