Impact and abrasion properties of the low carbon alloy steel with different chromium content in acid-ironstone slurry were investigated. The test was carried out by a MLD-10 tester with impact energy of 1.2 J. By analysing the morphology of worn surfaces and the metallographs of the subsurface of the specimen, the impact corrosion and abrasion mechanism was investigated. The results show that the percentage of wear mass loss decreases along with the increment of the Cr content. At the impact energy of 1.2 J, the impact corrosion and abrasion mechanism of low carbon alloy steel with 3% Cr content is the deforming fatigue wear,the mechanism of low carbon alloy steel with 6% Cr content is that shallow spallation due to accumulated deformation for a shorter time and removal of surface material due to multiple plastic deformation for a longer time, multiple plastic deformation belongs to the mechanism of low carbon alloy steel with 9% Cr content.