The invention discloses a dynamic pressure gas bearing structure provided with a radial supporting foil, comprising a bearing body and the radial supporting foil. The structure is characterized in that: a blocking groove tangent with the inner diameter of the axle hole of a bearing body is arranged on the bearing body; the radial supporting foil is inserted into the axle hole along the blocking groove in a tangential way; most of the front end of the foil is closed by winding a circle and along the radial direction that is contrary to the rotating direction of a rotor, and forms a closely attached elastic supporting part with the internal wall of the axle hole; a fastener is arranged on the blocking groove for closely fixing the rear end of the foil inserted in the blocking groove. Compared with the prior art, the radial supporting foil of the invention consists of two layers of foils; wherein, the elastic foil with bubbles has good rigidity and damping and restrains the vibration of the rotor and limits the increase of the amplitude of whirling motion, thus overcoming the shortcomings of complicate structure, requirements for high manufacturing precision and high cost of the existing dynamic pressure radial bearing and obviously enhancing the reliability and economical efficiency of the operation of turboexpanders.