This paper proposes a rotational speed sensor based on the magnetoelectric coupling effect. The sensor is composed of a permanent magnet array and a magnetoelectric composite FeSiB/Pb(Zr,Ti)O3. The permanent magnet array rotates with the gear to provide a stable sinusoidal alternating magnetic field in its surrounding space, which is simulated and analyzed by using the finite element simulation software. Based on the magnetoelectric coupling effect, the composite FeSiB/Pb(Zr,Ti)O3 senses the magnetic field information and transforms it into electrical information so as to realize the rotating speed measurement. The experiments of sensing distance and linearity are carried out. The proposed sensor is compared and verified by a coil sensor. The results show that the proposed speed sensor has good linearity in the speed measured range, and the sensing distance can reach 15 mm. At the same time, it can be used for low-speed measurement. This kind of speed sensor has broad application prospects in the field of rotational speed measurement.