The present invention relates to an 81-facet diamond with a 10-heart-and-10-arrow structure inside. The diamond comprises 10 main crown facets (3) and 10 main pavilion facets (1). The diamond further comprises one table facet (4). Crown star facets (7) are disposed at places where the main crown facets (3) are connected to the table facet (4), and the number of the crown star facets (7) is 10. Crown small facets (10) are disposed at places wherein main crown facet edges (6) are connected to the crown star facets (7), and the number of the crown small facets (10) is 10. Small sector facets are disposed at places where the main crown facets (3) are connected to the crown small facets (10), and the number of the small sector facets is 20. Auxiliary facets of the main pavilion facets (15) are disposed at main pavilion facetconnection places, and the number of the auxiliary facets of the main pavilion facets (15) is 20. The present invention has the following beneficial effects: the diamond is cut into 81 facets,
