An integrated imaging dual-view 3D display method and system based on a gradient-pitch microlens array. The system on which the method is based comprises a display screen (1), a barrier array (3), and a gradient-pitch microlens array (2). The display screen (1) is used for displaying a micro image array (4), and image primitives (5) of the micro image array (4) are corresponding to lens elements of the gradient-pitch microlens array (2) in a one-to-one manner. Each image primitive (5) in the micro image array (4) consists of a first sub image primitive (6) and a second sub image primitive (7). The first sub image primitive (6) and the second sub image primitive (7) of the micro image array (4) respectively form, by means of the lens elements of the gradient-pitch microlens array (2), a first viewing region (8) for viewing a first 3D scene and a second viewing region (9) for viewing a second 3D scene. By means of the method and the system, two different 3D scenes can be watched seen in two viewing regions, and wide-viewing-angle display is achieved.