Elastic joint of soft bag for infusion

The utility model discloses an elastic joint of a soft bag for infusion, which comprises an upper end opening, an infusion passage and a tail lug. The elastic joint is characterized in that two ends of the infusion passage are connected with the upper end opening and the tail lug respectively, the cross section of the lower end of the infusion passage is a circular, elliptical or diamond frame, the side wall of the lower end of the infusion passage is elastic and deformable, and the elastic joint of the soft bag for infusion is an integrated component. Since the tail lug at the lower end of the elastic joint of the soft bag for infusion is connected with the body of the soft bag for infusion, and the side wall of the lower end of the infusion passage is elastic and deformable, the cross section of the lower end of the infusion passage deforms into a slit when pressed by an upper mold and a lower mold during heat sealing for bag making, and then rebounded to the original shape approximately after bag making is