In order to realize the omnidirectional and low speed measurement of helicopter， a novel atmospheric data sensor is designed based on Bernoulli principle. The design of total static pressure sensor is put forward based on orthogonal test. And beyond that， servo mechanism including rotating elements and driving mechanism is designed and optimized to realize pitot tube rotating with air flow. For the offset of pressure output drift of atmospheric data sensor， an online data correction method is proposed. The experimental platform is established. The feasibility of the atmospheric data sensor and the veracity of the online data correction method is proved by the experiment data， and the measuring error of the air speed is reduced to less than 2% after online data correction.