An extraction method for center location of infrared light spot image in vision measurement was proposed. Firstly,the contour line of spot gray energy is segmented by the intersection of a group of threshold planes and infrared spot gray level energy distribution. The contour points and energy envelopes of each contour are obtained. Then,by using least square fitting method,the ellipse center of contour points is calculated. The centroid of spot energy envelope which is generated by threshold plane is gotten. The golden section point of ellipse center and envelope centroid is taken as the center of each contour. Finally,infrared light spot center location is extracted by the centers of each contour. Experimental results show that the proposed method has high accuracy for center extraction of infrared light spot image. The method has been used for the calibration of array static infrared earth sensor.