Helicopters operating various terrains, including concrete runways, sandy ground, beach and dune areas, and desert areas, face varying environmental sand concentrations. These concentrations significantly affect the erosion damage on the compressor blades of turboshaft engines. This study parameterizes the theoretical model of erosion damage for compressor blades based on sand velocity testing and titanium alloy erosion experiments. The dynamic model of erosion damage based on gas-solid two-phase flow was established. The distribution of erosion damage on rotor blades under typical environmental sand concentration levels was analyzed, with a focus on identifying the underlying causes. The extent of erosion damage was quantified for different environmental sand concentrations. Results indicate that the sand ingestion flow rates at the compressor inlet are 1.07e2 kg/s for beach and dune areas and 2.49e-2 kg/s for desert areas. As the environmental sand concentration increases from Level-4 (beach and dune areas) to Level-5 (desert areas), the erosion damage concentrated area on the pressure surface of the R2 blades expanded from 69% span to 52% span. The erosion distribution is influenced by multiple factors, including centrifugal forces from high-speed blade rotation, the shielding effects of guide blades and adjacent blades, the direction of sand particle impacts and the blade structural parameters. In desert areas, the R2 blades experience the most severe erosion, with damage levels 18% and 50% higher than those on the R1 blades and R3 blades, respectively. These findings offer new insights into the erosion damage assessment and inform the design of effective erosion protection strategies.