Sand　erosion　has　always　been　a　key　threat　to　the　performance　and　service　life　of　aero-engines.　The　compressor,　the　key　component　installed　at　the　front　of　the　aero-engine,　suffers　the　most　from　sand　erosion,　especially　compressors　serving　in　deserts.　Ceramic　hard　coating　is　a　traditional　way　to　improve　the　hardness　and　wear　resistance　of　cutting　and　grinding　tools.　It　may　also　be　used　to　improve　the　erosion　resistance　of　aero-　engine　compressor.　However,　the　mechanism　of　erosion　damage　is　complicated,　which　may　include　wear,　secondary　erosion,　anisotropic　erosion,　impact,　and　fatigue.　Recent　research　discovered　the　major　problems　with　ceramic　hard　coating　on　aero-engine　compressors.　In　this　paper,　these　following　problems　are　discussed:　the　design　of　coating　material　and　structure,　the　preparation　method　and　technology,　the　effects　of　droplets　and　clusters　of　coating　surface,　microstructure　and　characteristics　of　interface.　The　review　of　the　major　problems　and　possible　solutions　discussed　in　this　paper　may　contribute　to　the　future　research　on　erosion　coating　theoretically　and　practically.