The utility model discloses an impeller structure for a micro turbine flow meter. The impeller structure comprises an impeller arranged on a rotating shaft. The impeller structure is characterized in that a spiral blade is machined on the outer wall of the impeller, permanent magnet steel is arranged in the impeller, and the N/S pole of the permanent magnet steel points an axis perpendicular to the rotating shaft. By adopting the spiral blade, the friction resistance of fluid, which is generated on the spiral blade, is greatly reduced; the permanent magnet steel is cast in the impeller and uniformly and continuously runs together with the impeller, pulse is in proportion to the rotating speed of the permanent magnet steel, and the rotating speed of the permanent magnet steel is in proportion to the flow rate of the fluid, so that the measurement precision of the flow rate is improved.