Finite element method (FEM) was used to study the stress peak of stress S11 (radial stress component in X-axis) on the steam turbine blade surface of four typical erosion-resistant coatings (Fe2B, CrN, Cr3C2–NiCr and Al2O3–13%TiO2). The effect of four parameters, such as impact velocity, coating thickness, Young's modulus, and Poisson's ratio on the stress peak of stress S11 was analyzed. Results show that the position of tensile stress peak and compressive stress peak of stress S11 is far away from the impact center point with the increase of impact velocity. When coating thickness is equal to or greater than 10 μm, the magnitude of tensile stress peak of stress S11 on the four coating surfaces does not change with the coating thickness at different impact velocities. When coating thickness is equal to or greater than 2 μm, the magnitude of tensile stress peak of stress S11 of four coatings shows a trend of increasing first and then decreasing with the increase of Young's modulus. Meanwhile, the larger the Poisson's ratio, the smaller the tensile stress peak of stress S11. After optimization, when coating thickness is 2 μm, Poisson's ratio is 0.35 and Young's modulus is 800 GPa, the Fe2B coating has the strongest erosion resistance under the same impact conditions, followed by Cr3C2–NiCr, CrN, and the Al2O3–13%TiO2 coating, Al2O3–13%TiO2 coating has the worst erosion resistance.