The heat sink structure includes a vapor chamber, a heat pipe, and capillary elements. The vapor chamber includes a housing, a first capillary structure covering inside the housing, and a first working fluid filled inside the housing. The housing includes through holes and an inner top wall. Both ends of the heat pipe are inserted through the two through holes respectively and are exposed from the housing. The heat pipe includes a pipe body, a second capillary structure covering inside the pipe body, and a second working fluid filled inside the pipe body. Each of the capillary elements is connected to the inner top wall. One end of each of the capillary elements is in contact with the first capillary structure, and the other end of each of the capillary elements is in thermal contact with the heat pipe.