Abstract: Provided are a separator thickness adjustment device and method, and a winding electrode assembly production system. The separator thickness adjustment device includes: a mounting base; an active roller and a passive roller disposed at the mounting base in parallel to each other, in which each of the active roller and the passive roller is rotatable about its own axis, a gap is formed between the active roller and the passive roller, a separator passes through the gap, and a position of the passive roller relative to the active roller is adjustable to change a size of the gap; a first drive component configured to drive the active roller to rotate about its own axis to move the separator; and a second drive component configured to drive the passive roller to move towards or away from the active roller.