The invention discloses a buffering device for flexible sheet membranes and a wastewater filtering module with same, which comprise a positioning ring, wherein a shock-absorbing ring sheathes the sidewall of the positioning ring, the axis of the shock-absorbing ring is concentric with the axis of the positioning ring, and elastic parts are arranged on the end surfaces of the shock-absorbing ring.On a water-permeable pipe, a flexible sheet membrane located in between is fixed and clamped by two adjacent positioning rings, so the positioning ring is located between two adjacent flexible sheet membranes; and moreover, the ends, which are far from the shock-absorbing ring, of the elastic parts are in contact with the corresponding flexible sheet membrane. When the flexible sheet membrane shakes, due to the arrangement of the elastic parts, the shake amplitude of the portion, which is close to the positioning rings, of flexible sheet membrane is decreased and the shaking of the flexible sheet membrane is buffered, consequently, the stress applied on the portion, which is clamped by the positioning rings, of the flexible sheet membrane is decreased, the strength quality of the clamped portion of the flexible sheet membrane is increased, the flexible sheet membrane can smoothly filter water, and the tightness between the positioning rings and the flexible sheet membrane is increased.