To achieve linear motor mover position measurement, a subpixel displacement image detection method based on extended sampling phase correlation method (ESPCM) is proposed to improve measurement accuracy and antiinterference performance. Firstly, a linear motor position detection system is formulated. The stripe image sequences are captured in real time by a highspeed camera. Secondly, the edge feature extraction is performed on the stripe image. The crosspower spectrum of the adjacent stripe image is obtained based on the phase correlation, which is the integer pixel displacement of mover position. Then, the upsampling phase correlation is calculated based on the crosspower spectrum of the integer pixel neighborhood. The highprecision subpixel displacement measurement is realized and the actual displacement value is further obtained by system calibration. Compared with the traditional phase correlation algorithm, the proposed method can improve the measurement accuracy and noise suppression performance. Finally, an experimental detection platform is established to verify the effectiveness of the proposed algorithm.