The invention discloses a truss type three-freedom-degree double-pneumatic-gripper grabbing device. The truss type three-freedom-degree double-pneumatic-gripper grabbing device comprises a left large frame, a middle large frame, a right large frame, a transverse movement guide rail, a transverse movement rack, a transverse movement slide plate, a transverse movement motor, a transverse movement gear, a longitudinal movement guide rail, a longitudinal movement rack, a longitudinal movement slide plate, a longitudinal movement motor, a longitudinal movement gear, a middle large gear, a middle small gear, a lifting guide rail, a lifting rack, a lifting motor, a lifting gear, a lifting slide rod, a longitudinal movement limiting chain, a lifting limiting chain, a rotating cylinder, a right-angle triangular connection block, a first pneumatic three-jaw plate and a second pneumatic three-jaw plate. By means of the full-automatic truss type three-freedom-degree double-pneumatic-gripper grabbing device, the automatic blank piece supplementing and the automatic finished product piece grabbing are achieved, actions are rapid, the work efficiency is greatly improved, the actions are accurate, the error rate is greatly decreased, and potential safety hazards of manual work are avoided.