The invention discloses a rapid planeness measuring method. The rapid planeness measuring method comprises the following steps that firstly, a measured sample is placed on a horizontal table facet, and the measured surface of the measured sample faces downwards; secondly, a plurality of laser displacement sensors are mounted inside the horizontal table facet, and a measuring hole is formed in thetable facet; thirdly, the laser displacement sensors are started, meanwhile, the measured sample can be moved, and a plurality of positions on the surface of the sample are scanned through the laser displacement sensors; fourthly, the measuring result is automatically written into a collecting program by the laser displacement sensors, the maximum value and the minimum value are extracted, and thus planeness information is obtained; and fifthly, an output template is automatically filled with the measuring result, and a planeness testing report is printed. According to the rapid planeness measuring method, the planeness can be measured rapidly and accurately, and consistency is high.