Abstract: Efficient field flatness detecting and assessing is very important to the work of paddy land leveler and the development of precision agriculture. This paper designed a method which could measure field flatness based on laser scanner and Matlab, mainly including field flatness detecting and level assessing. This method managed to achieve field, point data by laser scanner, and to deal with the ranging data to realize three-dimensional reconstruction of the surface field, and to assesse the leveling accuracy and effect of the land leveler with fitting plane, elevation deviation and elevation standard deviation of the reconstructed land. Experiments were taken in experimental paddy fields, in which reconstructed land could well reflect the paddy field conditions, and elevation deviation fit normal distribution well achieved the elevation deviation within 3 cm. Therefore, the paddy field leveling assessing method designed by this paper was workable and effective. This method could provide reference to related research for automatic data acquisition and processing