This application discloses a display panel and a manufacturing method thereof, and a display device. A light-adjusting liquid crystal cell of the display panel includes a first substrate, a second substrate, a light-adjusting liquid crystal layer and a sealing layer. The ultraviolet light transmittance of the first substrate in a display area is less than a predetermined threshold, and the ultraviolet light transmittance of the second substrate in the display area is greater than or equal to the predetermined threshold. During the curing of frame glue, it can prevent pre-polymerized molecules from being exposed to light in advance. During the curing of the pre-polymerized molecules, it can make the pre-polymerized molecules have a cross-linking reaction to form a polymer network.