The invention discloses a washing powder packaging bag. The washing powder packaging bag comprises a bag body; the top and the bottom of the bag body are fixed together through hot pressing; a tearing line is arranged at one angle of the bag body; an elastic piece is arranged above the tearing line and tends to bend towards one side; and when the tearing line is torn, the portion, above the tearing line, of the packaging bag bends towards one side under the action of the elastic piece without blocking an opening below.