A display panel and a manufacturing method thereof, and a display device. The display panel includes a display area including a first and a second display area. The display panel includes: a base substrate; a driving circuit layer; anode structures located at the first display area, a gap being provided between adjacent anode structures, at least one anode structure including a functional layer and a first anode and an orthographic projection of the functional layer includes a portion not overlapped with an orthographic projection of the first anode; and a pixel defining layer including a pixel defining portion located in the gap. −0.1 microns≤d1−d2≤0.1 microns, wherein d1 is a thickness of the functional layer,






d
⁢
2

=


λ
⁡
(


2
⁢
m

+
1

)


2
⁢


❘
"\[LeftBracketingBar]"



n
⁢
1

-

n
⁢
2



❘
"\[RightBracketingBar]"





,




n1 and n2 are refractive indexes of the functional layer and the pixel defining portion respectively, λ is a wavelength of visible light, and m is an integer.