The invention discloses a control method of keeping same tension of double servo motor intermittent conveying mechanisms. By utilizing a structure that each servo motor has a moment feedback closed loop and a displacement feedback closed loop, thus being capable of feeding back an actual moment and an actual displacement signal, as a tension value exists between a main rubber roll and an auxiliaryrubber roll, momentnumerical values fed back by the two servo motors are compared with each other, and a tensioning degree of a membrane can be acquired; when a difference between the two momentnumerical values exceeds a preset numerical value, preset numerical valueregulation is performed on a displacement signal output by the auxiliary rubber roll in a third time quantum; the regulation numerical value is increased on basis of originally set displacement data, and dynamic comparison, accumulation and regulation are continuously performed by adopting multiple threads, so that the control method has the effects that same-phase synchronization of two rubber rolls can be kept to acquire relatively stable tension, and the bag manufacturing quality can be improved.