The present invention relates to a lead-free easy-cutting high-strength corrosion-resistant silicon-brass alloy and the preparation method and use thereof. The mass percent composition of the alloy is: 56˜60% Cu, 38˜42% Zn, 0.003˜0.01% B, 0.03˜0.06% Ti, and 1.0˜1.5% Si and 0.5˜0.9% Al or 0.5˜0.8% Si and 1˜1.5% Al, and the zinc equivalent of all components is between 48% and 50%. In the present invention, the phase composition and the distribution state of the alloy can be regulated by controlling the contents of Si and Al elements, as well as by adding a B and Ti composite grain refiner, in order to obtain a copper alloy with the advantages of excellent comprehensive performance of strength, process ability and dezincification resistance, a high production yield, and low costs, which can replace lead brass and bismuth brass for plumbing, bathroom and a variety of corrosion-resistant parts, and has a bright prospect of popularization and application.