A low-cost lead-free dezincification corrosion-resistant brass alloy for casting. The brass alloy contains: 60-65 wt. % of Cu, 0.05-0.25 wt. % of Pb, 0.05-0.8 wt. % of Al, 0-0.1 wt. % of Sn, and 0.05-0.16 wt. % of As, with the balance being Zn and inevitable impurities. Moreover, the equivalent weight of zinc X meets the requirements of the following formula: 35%