Abstract: A centroid detection method based on a single-pixel detector, including: S1: establishing a photoelectric detection and acquisition system, and generating three two-dimensional (2D) array matrices A, B and C; S2: generating, by letting element value of each column in the matrix A be the corresponding serial number of the column, element value of each row in the matrix B be the corresponding serial number of the row, and element value of the matrix C be 1, 2D modulation information having distribution of the matrices A, B and C; S3: modulating illumination light according to the mode of the 2D modulation information and projecting the illumination light to a target object or modulating, according to the mode of the 2D modulation information, an image formed by the target object; and S4: acquiring intensity value of target reflected light to obtain position parameter of the target centroid.