1. A rapid and high precision centroiding method for spots image comprising: A. convoluting the gray value of a pixel with a Gaussian filter and judging whether the result the gray value calculation exceeds a predetermined threshold, and if so, then proceeding to step B, and if not, then proceeding to step C; B. marking a current pixel with a flag to identify which spot the current pixel belongs to, then accumulating a product of the gray value and a coordinate value of the same spot; and at the same timer accumulating the gray value of the same spot; saving the results of the accumulations, respectively, and proceeding to step D; C. marking the current pixel as a background flag, then judging whether data in a buffer needs to be adjusted, and if so, then adjusting the data in the buffer, and if not, then proceeding to step D; D. judging whether all pixels of the image have been disposed of completely, and if not, then returning to step A, and if so then calculating a quotient of the accumulations of the product of the gray value and the coordinate value and the accumulations of the gray value, outputting the quotients as the coordinates value of the centroid of each spot image.