The invention relates to the technical field of metallurgy, in particular to a manufacturing method for a 65 Mn steel plate. The manufacturing method comprises the following steps of: smelting molten steel through a 300-ton converter to obtain casting blank, wherein molten steel consists of the following components in percentage by weight: 0.63-0.67% of C, 0.20-0.30% of Si, 0.9-1.1% of Mn, less than or equal to 0.020% of P, less than or equal to 0.015% of S, 0.01-0.05% of Al, and the balance Fe and inevitable impurities; performing hot-rolling, pickling and primary cold-rolling on the casting blank in sequence; performing annealing and secondary cold-rolling on a cold-rolled coil in sequence; and performing head and tail cutting, withdrawing-straightening and finishing-packaging on the cold-rolled coil in sequence. According to the manufacturing method for the 65 Mn steel plate provided by the invention, steel purity and the yield of the manufactured 65 Mn steel plate are obviously superior to those of a 65 Mn steel plate produced by conventional small-furnace steel making, so that usage requirements, on materials, of industries such as mechanical manufacturing can be met.