A pixel arrangement structure, a display panel and a display device are provided. The pixel arrangement structure includes a plurality of repeating units, each repeating unit includes one first sub-pixel, one second sub pixel and two third sub-pixels; the four sub-pixels of each repeating unit constitute two pixels, with the first sub-pixel and the second sub-pixel being shared by the two pixels; in a first direction of the pixel array, the sub-pixel density is equal to 1.5 times of the pixel density, in a second direction of the pixel array, the sub-pixel density is equal to 1.5 times of the pixel density; wherein, the first direction and the second direction are different directions.