Abstract: A new kind of anemometer to measure the air speed of the near-space low speed vehicle is introduced in this paper. This equipment is designed based on the theory that rotating the measuring arms increases the acquired dynamic pressure. Benefitted from this theory, the anemometer can measure the wind speed with reasonable precision in situations of ultralow dynamic pressure in the near space environment. A series of tests are completed in the near-space environment simulation wind tunnel in the 21th Research Institute of CETC, whose inflow air speed is available from 5 to 14 meters per second. The results show that the measured dynamic pressure curves are coincident with the sine function curves and there is a significant linear correlation between the amplitude of the dynamic pressure and the inflow airspeed. Based on the linear fit method, a calibration model of the anemometer is established.