The utility model discloses a to one side straight dual -purpose rat hole pipe, including the clamp that the outer circumference in rat hole pipe middle part clamped, the clamp is connected with the base link through incline swash bracket or perpendicular support, and the base link is connected with left back base through the left front base of round pin axle otic placode with the base, the rat hole pipe upwards passes the rat hole of rig floor face, is fixed with the flange at rat hole pipe upper end, and a pair of rolling bar is installed along the diametric(al) to the flange lower surface, and this is sat on a pair of semicircular seat of rig floor face rolling bar, the port welding has eccentric baffle under the rat hole pipe, and eccentric mouthful of eccentric baffle is as an organic whole through elbow bend and hammering union fixed connection. The utility model discloses a device has improved the top and has driven the security that the well drilling connect the thribble, can cushion the impact force of drilling rod below, protect the drill bit screw thread, prolong the life of drill bit, simple structure, installation convenient operation, work safe and reliable.