The jumping thread cutting device consists of a cutting blade screwed to a bearing, a cam anvil tube below the fixed blade, a connecting block, a fixing shaft over the connecting block, a locating cap, an eccentric cutter shaft inside the hole in the lower part of the connecting block and with one end fixed by the locating cap and the other end with bearing, a bearing, a gland for fixing the center of the cutting blade, and an anvil tube shaft penetrating the cam anvil tube to fix it. The present invention has the advantages of compact structure, high reliability, low cost, high longitudinal cutting precision and capacity of regulating the pressure to the longitudinal cutter during operation.