In order to satisfy highprecision measurement requirement of the linear motor mover position, a multipeak fitting phase correlation algorithm is proposed. The adjacent fence image is captured with a highspeed micro camera installed on the linear motor mover, and the phase correlation function of adjacent fence images is obtained by phase correlation algorithm. According to peaks distribution characteristics of the correlation function, the multimodal fitting method is utilized to acquire subpixel displacement of adjacent fence images. Based on the calibration coefficient of measuring system, the precise position of linear motor mover can be further acquired. Experimental results show that the subpixel image measuring method can achieve precise positioning, and the position detection accuracy of linear motor mover, can be up to 1/100 pixel, and it has strong robustness and high realtime performance.