A display panel and a manufacturing method thereof, and a display device are provided. The display panel includes a plurality of display units. Each display unit includes a first substrate and a second substrate opposite to each other. The first substrate includes a first base substrate and a first electrode, an electrostriction layer and a reflective trough which are disposed thereon. The second substrate includes a second base substrate and a second electrode and a reflective cavity body which are disposed thereon. A support is disposed between the first base substrate and the second base substrate, such that a distance between the first base substrate and the second base substrate is kept constant.