The application relates to a field of object connection and in particular, relates to a basic connecting block and a connecting block group. The basic connecting block includes a connecting block body, wherein at least one protrusion corner is provided on one side of the connecting block body and same number of inward recesses as the protrusion corner are provided on an opposite side of the connecting block body, and wherein a surface contour of the protrusion corner is consistent with that of the inward recess, the protrusion corners are connected with each other and the inward recesses are communicated with each other.