The invention provides a diamond bearing rope sling used in a grinding process. The rope sling comprises a column base and an outer sleeve; the column base comprises a column main body, the column main body is divided into an upper column body and a lower column body, a diamond placement position is arranged on the top of the column main body, the outer sleeve is arranged outside the upper columnbody in a sleeving manner and is in transition fit with the upper column body, the top edge of the outer sleeve is the edge with the section in an outer protruding arc shape, the height of the outer sleeve is smaller than the height of the portion below the outer wall face of the diamond placement position of the upper column body, and the invention further provides a diamond machining method. Thediamond bearing rope sling is arranged on a diamond placing machine, a solid round diamond to be ground is placed on the diamond placing position, use is achieved in cooperation with the diamond placing machine and fine grinding software, the grinding face angle of kite facet grinding of a round diamond on an automatic diamond grinding machine can be obtained, use in cooperation with the diamondbearing rope sling is achieved, round diamond kite facet fine grinding on the automatic diamond grinding machine can be directly achieved, and the whole production efficiency is improved.