An integrated imaging 3D display device based on a gradually-changing pitch micro lens array comprises a display screen (1) used for displaying a micro image array (4), and comprises a gradually-changing pitch micro lens array (3). In the gradually-changing pitch micro lens array (3), the horizontal pitches (Hi) of lens units on the same row are the same; the perpendicular pitches of lens units on the same line are the same; each horizontal pitch is gradually increased from the center to the edge; the horizontal pitches (Hi) and the perpendicular pitches of image units in the micro image array (4) are separately the same as the horizontal pitches and the perpendicular pitches of the lens units corresponding to the image units. When the integrated imaging 3D display device based on the gradually-changing pitch micro lens array (3) is used for imaging, the horizontal view angle (θ) is independent of the number of image units in the micro image array (4), so that the horizontal view angle (θ) of the integrated imaging 3D display device is increased.