The invention discloses a fully-hidden type furniture board connecting part. The fully-hidden type furniture board connecting part comprises a stand column, the outer wall of the stand column is connected with multiple transverse rods through a connecting mechanism, the connecting mechanism comprises a supporting shaft, a vertical shaft, a conical driving wheel, a conical driven wheel, a casing pipe and a thread pipe, a second check ring is arranged at the position, in the axial direction of the vertical shaft, of the top face of a square groove of the stand column, an inner six-edge groove isformed in the top face of the vertical shaft, an anti-loosening mechanism is arranged on the bottom of the vertical shaft, and enables the stand column and the transverse rods to be firmly connected,the vertical shaft can freely rotate on the anti-loosening mechanism, and the thread pitch of the connecting position of the supporting shaft and the stand column is larger than the pitch of the thread pipe. The fully-hidden type furniture board connecting part is convenient to mount and dismount, operation is easy and convenient, a locking structure and the anti-loosening mechanism are arrangedinside, connection of the transverse rods and the stand column is firmer and stable, fully-hidden design is adopted, and the connecting part is fashionable and beautiful and suitable for furniture such as tables and beds.