The work aims to study friction and wear properties of AlSi-ployster seal coating in aero engine gas path seal pair. AlSi-ployster seal coating sample was prepared by taking advantage of plasma spraying technology. A full-scale bench test apparatus was utilized to study failure mechanism of low-temperature seal coating abradability. Seal coatings of low hardness, medium hardness and high hardness, scratch morphology and surface roughness at low and high scraping speed were observed using 3D laser scanning confocal microscope and SEM (scanning electron microscopy), respectively. Scratch section profile depth of coatings of different hardness was 150 μm, 350 μm and 360 μm, respectively, and surface roughness 16.236, 22.155 and 47.300 μm; scrape depth of the coatings increased significantly at high scraping speed (280 μm, 570 μm and 570 μm). Coatings of different hardness exhibit different scraping mechanisms, scraping mechanism of low-hardness coating (HR15Y 45) is mainly adhesive wear, medium-hardness coating (HR15Y 60) micro cutting and high-hardness coating (HR15Y 75) corrosive wear and abrasive wear. Compared with effects of hardness on coating performance, blade tip velocity has significant influence on scratch depth. The scratch depth increases obviously at high scraping speed. Scratch surface roughness and profile depth are important indicators of measuring coating performance.