The present invention provides an X-ray image sensor, a flat panel detector, and an image acquisition and correction method of the flat panel detector. The X-ray image sensor at least comprises a sensor panel, a pixel array, m first row scanning lines, m second row scanning lines, n first column read-out lines, and n second column read-out lines; the pixel array is located on the sensor panel andis composed of m*n pixel elements of the same size, wherein m and n are natural numbers greater than or equal to 1; the pixel elements at least comprise signal pixels for performing photoelectric conversion on useful signals and correction pixels for collecting interference signals, wherein the signal pixels and correction pixels are arranged alternately; and the m first row scanning lines, the msecond row scanning lines, the n first column read-out lines, and the n second column read-out lines are located on the sensor panel. According to the X-ray image sensor, the flat panel detector, andthe image acquisition and correction method of the flat panel detector of the invention, the X-ray image sensor and the flat panel detector are improved and optimized, so that the X-ray image sensor and the flat panel detector are immutable to interference signals in time and space, and the influence of the above-mentioned interference signals on images can be eliminated through a correction mode.