Traditional eddy current based multi-cycle displacement sensors are difficult to solve the problem of absolute position identification after power failure and restart due to the periodic repetitiveness of the output signal. In this article, a new type of eddy current based bipolar linear displacement sensor is proposed. After theoretical and simulation analysis, it is verified that the amplitude of the induced voltage in the receiving coil shows a sine cosine variation with the sliding of the slide. A bipolar sensitive structure is designed to ensure accurate displacement measurement by means of a multi-cycle receiving coil at the upper pole. A single-cycle receiver coil is arranged at the lower pole to identify the cycle of the upper stage. The accuracy is improved by sensing signal offset and amplitude normalisation processing algorithms, and the sensor prototype is established in the laboratory and tested with a high precision electronically controlled translation table. The new multi-cycle bipolar eddy current linear displacement sensor has been tested to achieve absolute position measurement with a measurement error of 30 μm in the 0 ~ 60 mm range and a maximum non-linearity of 0. 08% . This breaks through the limitations of traditional multi-cycle eddy current displacement transducers where the absolute position cannot be identified.