The invention discloses a cutter of a vacuum sealer and relates to the technical field of vacuum sealing. The cutter is installed on a second sealing piece and comprises a fixed part fixed into the second sealing piece, and a cutting part connected to the fixed part. The cross section of the cutting part is triangular, and the shape of the cutting part adapts to the dimension of a cutter groove which is formed in a first sealing piece opposite to the second sealing piece. The end face of the second sealing piece is provided with a fixing groove, and the fixed part of the cutter is fixed into the fixing groove. According to the cutter of the vacuum sealer and a manufacturing technology of the cutter, the cutter is reasonable in structural design, especially, anti-corrosion treatment is adopted during cutting manufacturing, thus, the cutter can meet the machining requirement, the corrosion resistance and the abrasion resistance are high, and the service life of the cutter is prolonged.