Clamp unit and cover pasting machine thereof

The embodiment of the utility model provides a clamp unit and a cover pasting machine thereof. The clamp unit is used for clamping a liquid containing bag, the two opposite side faces of the liquid containing bag are provided with protruding parts protruding out of the side faces, the clamp unit comprises a first clamping jaw, the first clamping jaw is used for clamping the two opposite side faces of the liquid containing bag, the first clamping jaw comprises a first clamping arm and a second clamping arm which are oppositely arranged, and the first clamping arm and the second clamping arm are provided with receding parts; the receding part is used for receding the protruding part so that the clamping faces of the first clamping arm and the second clamping arm can be attached to the side face of the liquid containing bag. According to the embodiment of the invention, the first clamping jaw can avoid the convex part of the liquid accommodating bag, so that the clamping surfaces of the first clamping arm and th