Wafer pre-alignment control method

The invention provides a wafer pre-alignment control method. The wafer pre-alignment control method comprises the following steps: sampling data; preprocessing the data; detecting a notch area; wafer eccentricity calculation; calculating a gap angle; adjusting the position of the wafer, obtaining edge data in the rotation process of the wafer through a pulse triggering mode, removing the influence of the motion performance of pre-alignment equipment and/or acceleration and deceleration starting on data sampling, and improving the precision and efficiency of data sampling; a second radius and a first center coordinate of the gap area are calculated by using a least square method to serve as prior position information, and then a third radius and a second center coordinate of the gap area are calculated by using an LM fitting iterative algorithm, so that fitting of a second calculation data acquisition point of the gap area is realized; and the identification precision of the gap region is improved. According t