By using the self-made test equipment of single-disk base cutter, high-speed photography tests on the damage process in cutting sugarcane stalk with smooth-edge blade were done. Sugarcane stubbles' damage modes of “no damage”, “edge damage”, “split damage” and “shatter damage” under one-blade cutting or two-blade cutting process were individually studied. The influences of cutting speed and cutting modes on damage modes were also researched. It is found that the damage of the stalk in cutting mainly expressed as stalk's bark or core tearing, and stalk splitting. When two-blade cutting, the stalk was twisted in the first blade cutting, the top segment's bark and core were tore seriously, and the stubble damaged lightly than in one-blade cutting. The smooth blade's cutting speed should be above 22 m/s in order to meet the requirements on stubbles' cutting quality of sugarcane harvester.