An optical sensing device includes a shell, a partition structure, a pivot, a shading member, at least one light emitting member and at least one optical sensing member. The shell is formed with a black-body condition space having an arrangement chamber and a shading chamber adjacent to and communicated with the arrangement chamber. The partition structure partitions the arrangement chamber into a light emitting chamber and at least one optical sensing chamber. The pivot is set in the shading chamber. The shading member is located in the shading chamber and pivotally connected to the pivot. When the optical sensing device is tilted, the shading member is rotated in accordance with a tilting azimuth. The light emitting member is located in the light emitting chamber and projects a light beam. The optical sensing member is located in the optical sensing chamber and senses the light beam.