The invention discloses a jam releasing device for well pipes in unconsolidated formation; the jam releasing device is composed of a hollow cylindrical impact bar and a cylindrical inside band fixedly connected in the middle part of the impact bar; the axle line of the inside band is parallel to that of the impact bar; the longitudinal section of the inside band is trapezoidal; an inclined wedge surface which has a 10 to 15 degree included angle with the axle line of the impact bar is formed at the lower part of the impact bar; a duck-bill hole is formed at the bottom of the impact bar; a plurality of spiracles facing the side of the inside band is arranged in the middle of the impact bar; the high-pressure current ejected from the duck-bill hole at the bottom of the impact bar can wash matters jammed at and adhered to the outer wall of the well pipe back to the ground; the axis of the spiracles facing one side of the inside band in the middle of the impact bar has different included angles with the horizontal line, and the spiracles can wash out the matters jammed and adhered between the inner wall of the inside band and the outer wall of the underground well pipe from different directions so that the jam releasing of the well pipe can be carried out more quickly and thoroughly.