The invention provides a rust-proof amorphous alloy and a manufacturing method thereof, and belongs to the technical field of magnetic material manufacturing. The rust-proof amorphous alloy comprisesthe following element components in percentage by mass: 4.5%-6.8% of Cr, 6.2%-8.5% of Si, 2.5%-3.6% of B, 1.2%-2.5% of Mn, 0.5%-1.2% of C, 0.5%-1.2% of P, 0.3%-1% of Sn and the balance of Fe. Throughoptimization of the alloy element components and the ratio, the amorphous alloy product with good rust-proof performance and good soft magnetic performance is obtained.