The invention discloses an iron-containing Al-30Si aluminum alloy and a preparation technique thereof. The high-silicon aluminum alloy is prepared by pouring an aluminum alloy molten mass with 750 DEG C into a metal mold with 200 DEG C in an atmospheric environment. The Al-30Si mother alloy is prepared by the following steps: smelting industrial pure aluminum with the purity of higher than 99.8 Wt% and silicon metal with the purity of higher than 99.5 Wt% in a graphite crucible by using a well-type resistance furnace, keeping the temperature at 900 DEG C for 4 hours, carrying out refining and degassing on the alloy liquid with hexachloroethane at 750 DEG C, and keeping the temperature for 30 minutes. The element iron is alloyed by adding a Al-10Fe alloy at 780 DEG C and keeping the temperature for 30 minutes. The high-silicon aluminum alloy is composed of primary silicon, eutectic silicon, alpha-Al, Al-Fe and other phases, and comprises the following chemical components: 30.0 Wt% of Si, 0.2-1.4 Wt% of Fe and the balance of Al. The tensile strength is 180.4-222.2 MPa, the hardness is 38.6-52.8 HBW, and the resistivity is 0.12-0.23 ohm m.