Linear motor traction requires real-time and accurate feedback of rotor position and speed information for closed-loop control, in order to achieve functions such as constant speed cruise and fixed-point parking. However, electromagnetic sleds run in a long distance and non-contact way under the outdoor complex magnetic field environment, making their positioning and speed measuring technology unable to inherit from traditional wheel rail transportation and industrial machine tools. Presently, the main position and speed measuring methods that suit on maglev trains are faced with limitation from their basic principle or high cost. Aiming to solve the above problem, inspired by the structure of vernier calipers, this work proposes and designs a new position and speed measuring system. The principles of improved positioning accuracy, motion direction discrimination and position measurement are elucidated through theoretical analysis. proving the feasibility of the positioning and speed measuring scheme. The position prediction algorithm and Kalman filter algorithm are designed to further improve the accuracy and real-time performance. The corresponding hardware circuit and software program are designed and the positioning and speed measuring system is implemented. And, a synchronous belt guide rail verification platform is built to verify the designed system. Test results show that the system can achieve the designed positioning accuracy, and performs well in terms of real-time performance, accuracy, and engineering application value. Finally, the positioning and speed measuring system is applied to electromagnetic levitation propulsion platform.