The invention relates to a box cover assembling device of an automatic tissue clamp assembling machine. The box cover assembling device is matched with the automatic tissue clamp assembling machine for use and is used for automatically assembling a tissue clamp into a tissue clamp loading box and automatically packaging a plastic box cover on the tissue clamp loading box. The box cover assemblingdevice of the automatic tissue clamp assembling machine comprises a sliding base, a box cover transferring cylinder, a fifth sliding block, an installation plate, an installation plate, a carrying cavity box, a push-out block, a push-out cylinder, a push-out cylinder installation plate, a second pen-shaped cylinder, a lifting cylinder, a second cylinder installation plate, a third guide rail, a third sliding block, a second limiting buffer base, a fourth guide rail, a second buffer block, a second buffer block base, a guide rail installation plate, a second stand column, a fourth sliding block, a lifting cylinder installation plate and a box cover optical fiber sensor detection mechanism; the box cover transferring cylinder is installed on the upper part of the installation plate; the installation plate is installed on the workbench; the fifth guide rail is installed on the installation plate; the sliding base passes through the fifth sliding block; the second guide rail installation plate is mounted on the workbench on one side of the box cover feeding device through the second stand column; and the fourth guide rail is installed on a second guide rail installation plate.