In order to acquire high precision robot pose measurement when robot moves in large range, we propose a large field of view vision method based on zoom lens. Homography matrix between image matching points is used to dynamically calculate internal parameters while zooming. Camera coordinate system transformation is united according to target pose before and after zooming. In addition, by taking distortion into consideration, we introduce PnP algorithm which is related to zoom parameters and implement parameters optimization. We also propose a two-step zooming control strategy based on zoom and focus for dynamic pose measurement, as well as a target plate position measurement algorithm based on image template, which can detect and distinguish the mark points in any visible effective position of the target. Large number of measurement experiments including signal point error experiment and large scene tracking experiment are carried out to verify the effectiveness of the system. The experiment data show good performance in both pose measurement error and measurement range. Under different zoom parameters, the precision of single point measurement is high, as the average position precision is up to 21.8 μm. In the range of 400-1600 mm, position error is 0.09 mm which cannot be realized with ordinary fixed focus camera. Multiple experiments show that zoom camera can be used to measure during the range of 178.7461 to 9022.31 mm. The proposed method has an extensible measurement space and an advantage of position and orientation measurement in the case of variable measurement range with limited camera motion.