An image target was designed based on the principle of maximum length sequence（MLS）, using monocular vision and laser displacement sensor carried out One-dimensional absolute displacement test. In a relatively ideal laboratory environment, It’s show the standard deviation of the system’s repeated location detection data was less than 1 μm. According to the actual application environment and system installation status, for loss of focus from the lens, uneven illumination, deflection of the target and tilt of the lens may cause the detection error, conduct comprehensive experiments and analysis, The repetitive positioning of the one-dimensional absolute displacement detection system is discussed and proposed the method of improved. The experimental results show the standard deviation of the repeated positioning measurement data detected by one-dimensional displacement is less than 1 μm when the lens is out of focus; That the standard deviation of the non-uniform measurement data of lighting was less than 1 μm by improving the algorithm; When the targets under the condition of not greater than 5°, The standard deviation of the repeated positioning measurements is no more than 1 μm; And the camera angle is not greater than 3°, the standard deviation of the repeated positioning measurements is less than 1 μm. The last, the one-dimensional absolute displacement measurement is systematically calibrated by using laser displacement sensor. Under the above environment and installation error conditions, the root mean square error of the system measurement data is limited to 2 μm after the calibration.Test experiment and data analysis show the one-dimensional absolute displacement detection system is based on the principle of maximum length sequence can achieve high precision non-contact precision displacement detection, the system structure is simple and low requirement to implement process, advantages of easy installation and debugging.