To address the issue of airspeed measurement based on the acoustic vector sensor, an airspeed estimation algorithm based on the temporal and spatial expansion MUSIC algorithm is proposed. Firstly, it is concluded by theoretical analysis that only two wavefronts are superimposed at any point in the Mach cone formed by the supersonic flow, and that the two wavefronts can be considered to be created by two coherent “equivalent sound sources”.On this basis, the distribution model of the sound wave in the supersonic steady flow is built. Then, by employing the measurement model of the acoustic vector sensor, the supersonic airspeed estimation is realized based on the temporal and spatial expansion MUSIC algorithm. A failure analysis of the measurement model is carried out, and the estimated CRB bound is derived. The simulation results verify the effectiveness of the proposed algorithm.