Aiming at the problem of timeconsuming and high cost of measuring and calibrating the robot at the end of the existing equipment,a noncontact rapid detection method based on machine vision was proposed.The position information of the robot end was extracted by using the center information of the robot head end circle,and the improved Canny edge detection was used to locate the target edge.The improved Hough circle transform was used to extract the target position information quickly and accurately.The straightness of the ends was evaluated by the least squares method.The straightness error was corrected by modifying the code that controls the cartesian robot.The experimental results show that after two compensation,the straightness accuracy of the straight line at the end of the robot controlled by code is up to 0.1 mm.