Rail gauge and wear detection is a key technology to ensure the safety of train operation. The efficiency of traditional manual detection is low， and the large-scale track inspection vehicle has high detection and maintenance costs. Therefore， there is a lack of effective equipment and method in daily track inspection and maintenance to meet the increasing demand for track inspection. To solve this problem， a method of gauge and wear detection for portable track inspection trolley is proposed. In order to obtain the three-dimensional coordinate value point set of the track left and right track contour line in the same world coordinate system， the laser vision inspection model and system calibration method are constructed based on the light plane equation， machine vision three-dimensional reconstruction theory and camera calibration technology. By using the improved closest point algorithm to match the measured data point set with the standard rail point set， the rail gauge and wear can be calculated. Finally， the experimental verification is carried out by building a test system， and the results showed that the maximum measurement deviation of the method is less than 0.1 mm， which can meet requirements of the track daily maintenance， and provide technical guarantee for the safety of train operation.