A vacuum machine for zipper a bag comprising a casing, a motor, vanes, a suction mouth, a suction opening, a vent, a power supply, a switch and so on, wherein the suction opening is disposed corresponding to the vanes; the suction mouth is of tubular shape and is exposed out of the casing, and the rear end of which connects to the suction opening, wherein it also comprises a clamping member that connects with the casing and surrounds a section of the suction mouth; a clamping gap is formed between the clamping member and the suction mouth; the clamping member comprises an upper clamping member and a lower clamping member which are disposed substantially parallel to each other, thereby forming a clamping gap opening, the width of which is between 2 mm and 5 mm. The vacuum machine is simple in structure, small in size, convenient for use, highly flexible and suitable for zipper bags of different sizes and types. It not only vacuums zipper bags, but also securely seals the zipping strips of zipper bags, thereby solving the problem of difficulty in sealing the zipping strips accurately.