High-Mn steels have been intensively developed in steel industries due to their excellent mechanical properties and low density. However, the weak surface properties of these steels significantly limited the production and application scope. Various surface modification solutions were proposed, but they were not suitable for mass production or degraded the physical properties of base materials. Here, a new solution is proposed for mass-producing an ultra-thin multilayer clad steel sheet using an additive manufacturing process without changing the superior mechanical property of the high-Mn steel. Functionally graded multilayers from high-Mn steel to high-strength low-alloy steel have been deposited onto a high-Mn steel slab by a powder-fed type additive manufacturing process to improve its surface properties. During the deposition at high laser intensities, solidification cracks appeared in the first and second layers. The hot crack susceptibility of the functionally graded interlayers was elucidated by employing thermodynamic solidification calculation and thermo-mechanical analysis.