Abstract: Disclosed are a corrosion-resistant marine composite steel plate and a manufacturing method therefor. The corrosion-resistant composite steel plate has a two-layer structure, wherein one layer is duplex stainless steel, and the other layer is marine carbon steel; said duplex stainless steel comprises the following components by weight: C?0.03%, Mn?2.00%, Si?1.00%, Cr: 21.0-23.0%, Ni: 4.5-6.5%, Mo: 2.5-3.5%, N: 0.08-0.20%, P?0.02%, S?0.025%, and the balance being Fe and inevitable impurities; and said marine carbon steel comprises the following components by weight: 0.03%?C?0.13%, Si?0.50%, Mn: 0.90-1.60%, P?0.020%, S?0.025%, Cu?0.035%, Cr?0.20%, Ni?0.40%, Nb: 0.02-0.05%, Ti?0.02%, Mo?0.08%, Al?0.015%, and the balance being Fe and inevitable impurities.