The utility model discloses an stretchable wringing mechanism for a through-type wringing machine, which belongs to the leather processing field and is used for solving the problems that the existing processing process is poor in stretching effect, poor in wringing effect, and low in working efficiency. The stretchable wringing mechanism for the through-type wringing machine comprises an stretchable conveying mechanism and a wringing mechanism, wherein the wringing mechanism comprises an upper group of wringing device and a lower group of wringing device; the upper group of wringing device comprises an upper extruding rollers I and II; the lower group of wringing device comprises lower extruding rollers I and II; the upper extruding roller I and the lower extruding roller I are symmetrically arranged from top to bottom; the upper extruding roller II and the lower extruding roller II are symmetrically arranged from top to bottom; the wringing mechanism further comprises an extruding drive mechanism which is connected to the upper group of the wringing device and used for pressing down the upper extruding rollers I and II. Compared with the prior art, the pressure of one upper extruding roller is shared to two lower extruding rollers, so that the wringing capacity is increased by 60%, and therefore, the moisture content of the leather is greatly lowered.