A lead-free free-cutting corrosion-resistant silicon-bismuth brass alloy, including the following: between 60.0 and 65.0 wt % of Cu, between 0.6 and 1.8 wt % of Si, between 0.2 and 1.5 wt % of Bi, between 0.02 and 0.5 wt % of Al, less than 1.5 wt % of Ni+Mn+Sn, between 0.01 and 0.5 wt % of La—Ce alloy, between 0.002 and 0.02 wt % of B, with the remainder being Zn and inevitable impurities, wherein the total amount of impurities are no more than 0.5 wt %.