A displacement sensor with smaller volume and lower cost is needed for magnetic suspension control system. A transverse flux displacement sensor based on eddy current sensors is studied. The sensor analysis is based on its working principle. The parameters of excitation coil and induction coil are designed by particle swarm optimization， and the design process of the transverse flux sensor is simplified. The developed displacement sensor has a sensitivity of 7.2 V/mm， a linearity of 1.7%， and a detection range of ±0.5 mm. The sensor is applied in a magnetic levitation permanent magnet synchronous motor system. When the motor speed is 20 000 r/min， the high-speed magnetic levitation rotor still maintains stable operation. The transverse flux displacement sensors developed in this paper can meet the requirements of magnetic suspension motor displacement detection and suspension control， and achieve the control effect of similar products.