The invention discloses a method and a mechanism for equivalently lowering and folding cloth woven by a circular knitting machine according to cloth quantity. The cloth woven by the circular knitting machine is fed out after passing through a buffering temporary storage mechanism which can store the cloth temporarily and is partitioned into three section cloth lengths; the decrement of a third section cloth length on the lower side is equal to the summation of the increment of a first section cloth length and the increment of a second section cloth length; the increment of the first section cloth length is equal to that of the second section cloth length; the increment of the third section cloth length is equal to the summation of the decrement of the first section cloth length and the decrement of the second section cloth length; the decrement of the first section cloth length is equal to that of the second section cloth length; and the three section cloth lengths are mechanically complemented with one another through the buffering temporary storage mechanism, so that cloth above a cloth folding rod which moves and lowers the cloth in a reciprocating way keeps fixed tension, and cloth continuously woven by the circular knitting machine is equivalently lowered and folded on a cloth carrying plate if the cloth above the cloth folding rod keeps the fixed tension.