In the report ,the author makes deep research on three dimensional rofile measurement using the method of line structure light. A hardware circuit developed is used to get the center position of light sectioning ,and the measuring speed is improved. A double CCDs compensation technology is used to improve the measurement precision. An easy and effective cali2 bration method of the least squares to fit the parameter of system structure is used to get the relative coordinate relationship of objects and images of light section in the directions of height and axis. Sensor scanning segment by segment and layer by layer makes the measurement range greatly expanded. The experimental results show that the line scanning measurement machine has advantages in measurement precision , range and speed , and has great values in applications.