The invention discloses an all-optical information acquiring device and method based on a four-zone phase delay array. The all-optical information acquiring device comprises a front telescoping system, a four-zone phase delayer assembly, a polarizer, a four-face pyramid prism, a Savart polariscope, a polarization analyzer, an image-forming mirror and a CCD detector. The front telescoping system, the four-zone phase delayer assembly, the polarizer, the four-face pyramid prism, the Savart polariscope, the polarization analyzer, the image-forming mirror and the CCD detector are sequentially arranged in the direction of a main light axis of incident light. An xyz coordinate system meeting the right-hand rule is established, and the main light axis is the Z axis. A first set of delayers is located between a second set of delayers and the front telescoping system, the included angle between the fast-axis direction of the first set of delayers and the x axis is 0 degree, and the included angle between the fast-axis direction of the second set of delayers and the forward direction of the x axis is 45 degrees. The all-optical information acquiring device can realize all-Stokes vector polarization information detection without causing reduction of the resolution, and has no special requirement for an incident spectrum.